To a striking degree, the White House staff of Ronald Reagan and Jimmy Carter reflect the personalities of their masters. The president sets the tone, and the staff -- a creature with no other purpose than to serve him -- adapts.

Reagan and Carter are vastly different men, and the Californians replacing the Georgians in top White House staff positions promise at least to begin with a very different approach.

Both presidents and their closest advisers worked for a long time to get the White House prize, but one of the most evident distinctions between Reagan and Carter and therefore their men is how they feel about themselves.

Carter made a fetish of his outsiderness. For all of his ambition and intelligence, his insecurity is palpable. He always has been a man striving, working hard (you can sense the strain) to climb the next hurdle toward which his giant ambition drives him.

Reagan, although equally an outsider lacking federal government experience, is relaxed and selfconfident, clearly content with who he is and unembarrassed at not being the things he is not.

The Carter team came to the capital with a chip on its shoulder and immediately circled the wagons. Reagan's men are aware that elements in Washigton are suspiscious of a group that helped make a 69-year-old former actor president, but they sailed into Washington confident they could win friends and allay misgivings. The capital proved an easy conquest.

Reagan plunged into a round of Washington social events, and his aides drove in after him. There is no stigma in the Reagan camp about knowing one's way around Washington, even its bars. James Brady, Reagan's press secretary, was asked whether he would work in the same office Jody Powell used in the White House. He said he would.

Then he was asked jokingly about a bar that Powell and some White House reporters and staffers have visited from time to time. "Do you know where the Class Reunion is?"

"Sure. I knew where the Class Reunion was long before Jody Powell did," Brady said with a smile.

At the top of the Carter staff was Hamilton Jordon, in his early 30s, a shy man, uncomfortable with strangers or in the limelight.

The senior Reagan aide is Edwin Meese III, almost 50, gregarious, able to talk for 30 minutes nonstop without saying a jot more than he wants to. "You'd make a good prisoner of war," a colleague once told Meese after watching him give an interview. He is good at remembering names and unfailingly polite to outsiders who cross his path even though they are interrupting his busy schedule.

Reagan's election victory propelled Meese into a whirlwind of public activities. Acting as both staff director and chief enunciator of policy for the new administration, he has sped from transition meetings to television talk shows to press briefings to sessions with Reagan.

With Meese seemingly in charge of everything except redecorating the White House and Reagan spending much of his time in seclusion in Los Angeles, some reporters have taken to calling him "President Meese."

The term is an occasional joke now but, if Reagan continues to be in Rep. Barber Conable's term "somewhat disengaged," it could be heard with increasing frequency.

If Meese has appeared to be the most important transition figure, including Reagan, his loyalty to Reagan is unquestioned. Reagan once was asked who he would turn to if he were in trouble. "Ed Meese," he replied.

Adjectives such as "unflappable" follow Meese around.

His favorite word is "management," and Meese speaks often of the virtues of government copying techniques from the business world.

Recent history indicates that no president will repeat the organizational mistakes of his predecessor. Instead, since memories are very short, each president will happily follow a path well-traveled two or three administrations earlier while proclaiming it a new direction.

For example, Cabinet meetings are taken seriously and held regularly in one administration only to be scorned and rarely convened in the next. The White House staff organization follows cycles. Carter was determined to avoid the evils of the Nixon administration and refused to appoint a chief of staff in order not to get another Haldeman. What he got was bad management.

Reagan has watched the organizational fumbles in the Carter White House and comes to office with a promise of efficient management. Carter had poor relations with Congress. Reagan devotes much of his early attention to cultivating Capitol Hill.

Carter rejected the old ways of politics as discredited. Reagan wins applause for going back to old political practices, flattering and back-scratching to persuade people to go along with him.

Meese proved his toughness and how close he is to Reagan during the campaign when he defeated John Sears in a battle for control and then, like a gunfighting sheriff blowing the smoke from his six-shooter, declared a cease-fire in the struggle for Reagan's mind.

No one seems likely to challenge Meese's supremacy in the White House, in contrast to the Carter administration whose first days were soured by a power fight between Jordan and Jack Watson. Later, as Jordan demonstrated that he was not comfortable as a manager of the White House staff, the lines of authority became confused again, with Jordan disappearing from the public view while still playing a major role.

Meese and Michael Deaver, a public relations man who will be the third-ranking White House aide, have been with Reagan since his days as governor in California. They share what Nancy Reagan once said was an important quality in men who would be close to Reagan.

Both are cheerful and relaxed. "Ronnie likes things to be happy around him," Mrs. Reagan said. "He doesn't like differences, tensions -- he doesn't want to get on the [campaign] plane holding his stomach."

The stomach cramps flow both ways. George Reedy, who served a less constantly supportive master than Reagan, Lyndon B. Johnson, wrote in "The Twilight of the Presidency" that:

"A White House assistant lives a life of anxiety. There is no fixed point in his daily routine, other than the occasional smile of approbation or nod of approval that comes from the president."

Meese and Deaver have enough confidence in their boss' support to escape anxiety. Deaver, who has performed several duties for the Reagans throughout the years, sometimes seems to be half their adviser and half their son.

Between Meese and Deaver in the White House hierarchy will be James Baker III, the chief of staff, a man who worked for Jerry Ford to defeat Reagan's 1976 presidential bid and managed Vice President George Bush's 1980 campaign until Reagan defeated Bush for the GOP nomination.

Although Baker came to Reagan late, he is no stranger to Washington and brings to the White House years of experience in getting things done in Washington.

It is only the beginning for Reagan's staff, and their polished, polite self-confidence has not been tested yet.

When the going is easy, White House staffers always have found it possible to live and let live, but there is a paranoia that works in the White House and seems to attack every administration at one time or another, triggered by policy setbacks or unflattering press clippings. At such times, the friendly smiles disappear, and the talk turns to loyalty oaths for the insiders and a closed door for the rest.

Meese already has posted some warning signs.

"A president's staff should have a zeal for work and a passion for anonymity," Meese said in laying out guidelines for his subordinates. But, he added, "we certainly would never muzzle anybody."

The national security adviser will not quite be fitted with a muzzle, Meese also has explained, but he will not be given much access to a loudspeaker either.

After watching Henry A. Kissinger and Zbigniew Brzezinski become major foreign policy spokesmen as national security advisers, the Reagan team decided to model its administration on the days when the secretary of state was unquestionably the preeminent foreign policy adviser to the president.

Richard V. Allen is a less flamboyant man than his two predecessors and has agreed to the new reduced role for his White House post. Like his predecessors, Allen will brief the president daily.

That access has been turned into power by other advisers, but Meese told reporters before Allen was selected that he could guarantee that the national security adviser would not be allowed to grow new wings.

"I'm going to be the referee . . . or I should say the enforcer, that's a better way to put it," Meese said.

It has probably always been true that the more activist a president is, the more pressure his staff is under. A corollary that Reedy described is that the more autocratic a president, the more his staffers will be like courtiers to a king in their efforts to survive his whims.

Reagan promises to be the least autocratic president in many years and, in one important way, his lifestyle is going to change less when he enters the White House than did that of many of his predecessors.

The White House isolates the president and makes him see the world only through his staff, what he reads and what he sees on television. Reagan has long been protected by his wife and closest aides, and the isolation of the White House will be little different from what he has known either in his Los Angeles house or his ranch near Santa Barbara.

He also is remarkable among recent presidents in his lack of concern about his image. Reagan appears not to bother to watch much television news about himself nor to read many newspaper reports of his activities, while other presidents have watched three networks simultaneously and devoured a thick stack of newspapers daily. He spares himself and his aides a constant series of inquiries about how favorable or inaccurate items came to be published.

Even when something does anger him, Reagan seems unable to stay angry for long.

In early January, he told reporters he was "an irate husband" about what he called inaccurate stories about his wife. Seconds later, however, he turned his anger into a joke and left his audience laughing.

"Since the boss doesn't enjoy conflict, we can live without it, too," one Reagan aide commented with a smile.

In the Carter and Reagan administrations, the White House staff has one important player not only unelected but also unappointed -- Rosalynn Carter and Nancy Reagan.

In differing ways, each wife has at times seemed to take the business of running for president more seriously than her husband. While the Carters discussed national policy together, Nancy Reagan has said she will not participate in Cabinet meetings or intervene in policy deliberations. Yet, she is no less protective of her husband, and her recommendations on people carry weight with him.

Mrs. Carter reportedly took the election defeat the hardest in the Carter White House. Mrs. Reagan has said that when her husband is criticized she often gets so mad she sits in a hot bath.

Reagan said after he won the nomination that he was surprised by the change in how he was treated: "You're doing the same thing that you did when you were campaigning for the nomination, but suddenly the press is camped at your door every day, every minute. There isn't anything you can do without their attention."

The change from nominee to president is, if anything, larger. The test for the Reagan's is whether it changes their tone and, through them, that of their staff.