By all advance accounts, including his own as expressed to reporters yesterday, Richard V. Allen intends to keep a low profile in one of the most sensitive and potentially powerful posts in Washington -- assistant to the president for national security affairs. Such predecessors in the job as Henry A. Kissinger and Zbigniew Brzezinski began by making similar vows, but Allen seems more likely to keep them.

The 44-year-old Allen, chief foreign policy staff aide to Ronald Reagan during his 1980 presidential campaign, served in a similar capacity to Richard M. Nixon in his 1968 campaign and became deputy national security adviser in the Nixon White House, but was soon excluded from the most important matters by his senior associate, Kissinger. Allen left the White House for private industry in less than a year.

The methods of Kissinger and Brzezinski, whose high-profile reigns as security adviser led to internal disputes within government, have often been cited by politicians and policymakers as a major problem for U.S. diplomacy. Even Kissinger conceded in retrospect that his was "an unsound system."

Reflecting this dissatisfaction, Reagan pledged in an Oct. 19 television speech to restore coherence to foreign policymaking by "structural changes" to ensure that the secretary of state will be the president's "principal spokesman and adviser," and that the national security adviser will be a team player and coordinator. predicted that the White House national security adviser in the Reagan administration "will be a staff person and act like a staff person. He will be much less visible. He will be a coodinator and the NSC staff will be used as a coordinating vehicle rather than to formulate foreign policy." In the preliminary organization chart of the Reagan White House, Meese will be the immediate supervisor of Allen's work.

Despite these statements, Allen has been anything but invisible so far. In recent months he appeared as spokesman for the Reagan foreign policy on "Meet the Press," "Issues and Answers" and other national television programs as well as in U.S. News & World Report and other publications With the nomination of Alexander M. Haig Jr. for secretary of state, however, Allen has begun to fade from the limelight. He told reporters yesterday that "you're seeing a disappearing act right now."

Allen, for other reasons, did another kind of "disappearing act" on Oct. 30, when he resigned from the campaign in its final days because of conflict-of-interest charges against him. In announcing the resignation, Meese declared that Allen was innocent of any wrongdoing but that he was stepping aside in order not to distract attention from the issues of the campaign.

On Nov. 6, two days after Reagan's victory, Allen was back. On that day Reagan named him as a senior adviser to the transition team and a member of the interim foreign policy board, and the president-elect told a press conference "we find absolutely no evidence of wrongdoing whatsoever." Since then Allen has been the main link between Reagan and the foreign and defense policy aspects of the transition.

The conflict-of-interest charges leading to Allen's furlough from the campaign arose from a Wall Street Journal article reporting that Allen had carried on private business negotiations with Japanese companies while in a U.S. government trade post in the early 1970s. The article also charged that Allen claimed the right to benefit from a $120,000-per-year account that an associate obtained from Datsun, the Japanese automaker, as a result of Allen's activities.

Allen responded, and government records confirmed, that he was a private citizen when these events occurred. During the time in question, he served without pay on a govenment trade advisory committee whose members were free to carry on private business.

As a private business consultant, Allen was paid $10,000 per month for about six months as a trade adviser by Howard Cerny, a lawyer for Robert Vesco, who later fled the country aftercharges of swingling were brought against him.

In 1976, Allen was accused in a Senate hearing of having sought a $1 million campaign contribution for the Nixon reelection fund from Grumman International, a defense contracting firm, in return for pressure on Japan to buy a Grumman plane. Allen denied the accusation by a former Grumman official, and it has never been proven.

Allen, who holds B.A. and M.A. degrees from Notre Dame, was a senior staff member in the 1960s of the Georgetown Center for Strategic and International Studies, and the Hoover Institution on War, Revolution and Peace. Since 1972 he has been president of Potomac International Corp., a consulting firm he founded. He is married and has seven children.