A major study on new foreign policy options being prepared for President Reagan is expected to rank arms control with the Soviet Union at the top of the list, according to White House officials.

The purpose of the assessment, officials said, is to focus on three or four major policy areas on which the United States can best focus its efforts during the remaining two years of the current Reagan term.

The officials stressed that they are not talking for all involved in national security policy-making and that the president will not be making decisions on options growing out of the study until December.

But interviews with well-placed officials nevertheless strongly suggest, as one put it, that "the president will very strongly reinforce his emphasis on arms control, particularly the START," or strategic arms reductions talks, with Moscow that have just been resumed in Geneva.

The president's emphasis on this issue is surprising to some of his closest aides. Moreover, officials acknowledged, an important element in Reagan's general sense of encouragement is the still officially secret Soviet proposal put forth at the Geneva talks.

"If there has been one recurring theme in our morning meetings since January," said an aide involved in White House national security deliberations, "it has been that the president is terribly concerned about arms control. "Who would think that Ronald Reagan gives a whit about arms control," the official said.

"But it comes up three of four times a week. We may be going in to the Oval Office to talk about Latin America and he'll ask about arms control and how Ed Rowny is doing." Rowny, a retired Army general, is the chief U.S. negotiator at START.

As far as policy is concerned, perhaps the most important new development is the preliminary impact in Washington of the Soviet proposal advanced at Geneva.

Although never discussed publicly by either side, it has been reliably reported that Moscow has proposed a mutual cutback in long-range missiles and bombers to equal levels of about 1,800 for each side. This is a substantial cutback, equal to about 25 percent of Moscow's force of some 2,500 strategic weapons. It would require a cut of about 10 percent in the American arsenal of some 2,000 such weapons.

There are, however, several serious strings attached to the Soviet proposal, including a demand that also ties such reductions to an American pledge not to deploy shorter-range missiles in western Europe.

The Soviet proposal also doesn't go nearly as far as the Reagan proposal, which envisions a reduction to 850 missiles on each side and is meant to reduce the threat of a first strike by either side by reducing the forces that would be available for an effective surprise attack.

The Soviet proposal, which is still being analyzed here, has split officials into two groups. Many, who are very wary, "tend to focus on how great a distance we still have to go," one senior official said.

"But the president," he added, "tended to focus on how far they the Soviets have come from what anybody would have expected. He, too, feels there is a helluva long way to go," the aide said of Reagan, "but if you look at what they are going in to Geneva with today versus what they absolutely rejected in March of 1977, it's rather remarkable. So the president doesn't think we are there at all" meaning approaching an agreement "but he is encouraged that we can perhaps achieve something."

The reference to March, 1977, is to a proposal for very deep reductions in missile forces made by the Carter administration that the Soviets rejected.

The official would not say whether the United States would now move away in any degree from its opening proposal toward a possible compromise. Indeed he indicated there were many specific points about the Soviet proposal that had to be discussed first. But he suggested that by December, when the current round of talks is likely to adjourn, there would be another presidential review of the situation and probably a public statement.

Paradoxically, that statement could come at the time Reagan is recommending to Congress a go-ahead on the $23 billion "Dense Pack" plan for basing the new MX intercontinental ballistic missile. Foes of arms control in government have argued that expectations of progress weaken public support for defense expenditures that are necessary to produce a strong bargaining position.

The presidential review will be based in part on the analysis of the Soviet proposal by two officers, Adm. Jonathan Howe of the State Department, and Gen. Richard Boverie of the White House National Security Council staff, and by Richard Perle, an assistant secretary of defense for international security policy who has long been among those most skeptical of Soviet intentions.

The overall review of where American security policy should focus in the next two years has been under way for about two months, primarily by the NSC staff under the guidance of national security adviser William P. Clark.

Next month, officials said, the secretaries of state, defense and treasury, the directors of the CIA, the Arms Control and Disarmanent Agency and the U.S. Information Agency, and the chairman of the Joint Chiefs of Staff will be asked for their comments. The president then is expected to decide on the options and priorities.

Officials said, on one hand, this is a natural time for any administration to take a fresh look at where it is going. The next year, in particular, should be a time for freedom of action before the 1984 presidential election year impinges on flexibility. But they said that the arrival of George P. Shultz as secretary of state in July and the still relative newness of Clark in the top echelon of aides also contributed to the feeling that this was the time for another look.

There is no doubt, officials also acknowledged, that the ease of working with Shultz, as opposed to the tension that frequently gripped the administration during the tenure of Secretary of State Alexander M. Haig Jr., has contributed to the idea of a review.

Officials said that the new assessment began shortly after Shultz arrived and that the impulse for it came from Reagan. The president reportedly told Clark that "we have enormous opportunities in the next couple of years. But we risk missing them through diluting our effort, trying to do too much and not focusing enough on those three or four things which any administration can reasonably be able to accomplish."

The directive to Clark was to "lay out the spectrum of demands and opportunites to choose from . . . produce a pragmatic analysis of how U.S. interests can best be advanced" and then provide a road map on "how to get there from here."

The president reportedly provided some of his own "gut feelings" at the outset. One, which has already become clear, is that "the time had come" for action on the Middle East. The United States, it was said, simply could not protect its own interests in the region if the cycle of violence that erupts every few years is not broken.

Arms control was another of the president's gut feelings about where opportunities lie. If Reagan follows through on this, he will not be the first president to pursue arms control, an issue with considerable political appeal, as an election year approaches. President Carter, who withdrew consideration of the SALT II treaty from Congress after the Soviets invaded Afghanistan in 1979, subsequently campaigned hard on the need for arms control.

A third area that appears certain to get increased attention is Central America, although Reagan has not spelled out his thoughts on this as he has on arms control and the Middle East, officials said.

Interviews suggest that what can be expected on Central America is not so much a change in policy, which has been to give strong support to anti-communist governments in the region, but rather a public relations effort, lead perhaps by the U.S. Information Agency, to convince people that the United States has vital interests in the region.

The average American, officials believe, "could not say what those interests are, how they are threatened, why we should care or what we should do." In the NSC staff, the view is that American interests are threatened by the "defeat of pluralism" in Central America. This means socialist and Cuban domination of countries around the Caribbean, a region through which huge amounts of imported goods flow to the United States and American military supplies would move in a crisis to Europe from ports on the Gulf of Mexico.

Aside from these three major areas, one official said other issues include energy policy, relations with Japan and China, the chances for peace in Southern Africa, and the "terribly important" issue of East-West relations.

"It has become evident," the official said, "that we and our European allies have a different view of how East-West relations ought to be conducted and a different view of what Soviet intentions are. It is vital that we harmonize" these views and come to an agreed-upon way to operate, he said.