It is increasingly difficult for presidents to persuade talented people to serve in top executive branch jobs because of "petty aggravations," governmental disarray and the anti-Washington campaigns of Presidents Carter and Reagan, according to a new study of the presidential appointment process.

A survey of 536 presidential appointees in the last five administrations by the National Academy of Public Administration found:

*Increasingly rapid turnover in top federal jobs.

*Longer delays in Senate confirmations.

*Increasing reluctance to make the required financial disclosures that are more revealing as a result of post-Watergate changes.

*A widening gap between salaries of top government executives and their private sector counterparts.

*Longer work hours.

*Increasing numbers of appointees who said their government jobs had caused stress in their personal and family lives.

The report noted that the average length of service for presidential appointees is "just a shade over two years" and that one-third stayed for 18 months or less.

Members of the panel that prepared the report said a different attitude toward government service was a major part of the problem and that the current president and his predecessor had made things difficult for themselves by scorning government "as the problem, not the solution" in their campaigns.

"It's a big problem when you have two presidents running against the government and Washington," said Frank C. Carlucci, deputy secretary of defense in the Reagan administration and undersecretary of health, education and welfare in the Nixon administration.

"The emphasis should be on delivering effective and efficient government rather than just cleaning up waste, fraud and abuse on the way to dismantling government," he said. "People want to feel that they're doing something useful and carrying out a mission."

About 80 percent of the presidential appointees surveyed said they were thrown into their jobs without being told what the president wanted them to accomplish, what their relationship was to his overall program, how the federal government works or how to deal with Congress and the press.

Carlucci also described a deeper problem: "The executive branch has become so encumbered by statutory restrictions and burdens, mangled organizational structure, confused lines of authority and accountability . . . pervasive congressional micro-management . . . and a complex, burdensome, self-defeating and totally unstable budget process, which is now falling of its own weight, that the presidential appointee finds himself unable to achieve even the minimal program goals he and his superior have established."

The study recommended:

*Trimming the number of appointments.

*Limiting the period any senator can delay a nomination to five working days.

*Simplifying the financial disclosure form to require reporting of holdings in only two categories -- below and above a value of $10,000 -- rather than in the half dozen or more categories now required.

*Procedures for periodic salary adjustments.

*Thorough briefing and orientation procedures.

*Upgrading the prestige, visibility and access of the Presidential Personnel Office.

*Banning any solicitation or discussion of future private employment by any presidential appointee, but providing three months' severance pay.

*An annual 10 percent bonus for appointees who remain for more than three years.