The relatives, confidants, and advisors of the late President Kennedy gathered in Cambridge yesterday to celebrate the establishment of the "working part" of the Kennedy Library complex -- the Institute of Politics.

On hand to hear about the organization of the Institute and the renaming of the Graduate School of Public Administration (now the John F. Kennedy School of Government) were members of the Institute's new Advisory Committee, including Mrs. John F. Kennedy, Ambassador W. Averell Harriman, and C. Douglas Dillon '31, former Secretary of the Treasury.

Following a late afternoon meeting, the Advisory Committee joined 80 distinguished guests of the Harvard Corporation for dinner in the Holyoke Center penthouse.

President Pusey and Senator Robert F. Kennedy '48 addressed the closed dinner meeting, which was also attended by most of the Kennedy family, including Senator Edward M. Kennedy '54 and the mother of the late President, Mrs. Joseph P. Kennedy.

Eight Secret Service Men

Eight Secret Service men trailed Jacqueline Kennedy throughout the day. They smuggled her into Littauer Center for the afternoon meeting -- via the front door--while network television crews and news reporters waited patiently at the Center's rear door.

The press had been told that the complete entourage would arrive at the rear, but two members of the Advisory Committee -- Harriman and Mrs. Philip Graham, president of The Washington Post -- diverted their attention while the rest of the party entered by the main door.

Crowds were scanty all afternoon. Only a few curious law students and Faculty members with Littauer offices watched the arrivals from the stairwell of the Center. Guards at both doors demanded identification of all comers, explaining that "the FBI wants us to do this. They're everywhere."

At dinner time, however, about 200 students and Harvard Square workers crowded the Mt. Auburn entrance to Holyoke Center as the black-tie dinner guests arrived for the official opening of the Institute.

The crowd was quiet as Mrs. Kennedy, wearing a long gold satin gown under a black velvet cape, arrived on the arm of President Pusey. She had been preceded by Faculty members associated with the newly-named John F. Kennedy School of Government, friends of the late President, and former Kennedy aides.

A few moments later, the Senators Kennedy drove up to the entrance. Both were rushed from an afternoon political rally in Post Office Square, where they spoke in behalf of Massachusetts Democratic candidates. This was the brothers' first joint political appearance of the 1966 campaign.

While his brother hurried into Holyoke Center, Senator Kennedy of New York paused to shake hands with students lining the entrance. As they pushed around him, Kennedy grinned broadly, shouted "get back to work," and then disappeared into the elevator.

Earlier in the day, Richard E. Neustadt, Director of the Institute, made two important announcements about newly-organized programs. At the afternoon meeting, he released to the Advisory Committee the list of the Institute's first "honorary associates." These 11 prominent politicians will come to Cambridge for two or three days this year to meet with groups of undergraduates for informal, off-the-record interchanges.

McNamara Named Associate

The "honorary associates" and the approximate dates of their visits to Cambridge are Robert McNamara, Secretary of Defense, Nov. 6-7; Gerald Ford (R-Mich.), House Minority Leader, Nov. 16-17; Jerome Cavanaugh, Mayor of Detroit, Dec. 11-13; Lawrence O'Brien, Postmaster General, Jan 8-10; Arthur Goldberg, U.S. Ambassador to the United Nations, Feb. 12-14.