The people of Hong Kong accept the Sino-British agreement returning the colony to Chinese sovereignty after 1997, but with some serious reservations, according to a special Hong Kong government office opened in September to receive public assessments of the draft pact.

The assessment office's report, along with a report of an independent British team assigned to monitor its objectivity, comes just before debates in London over the Hong Kong issue.

Debate is scheduled for Dec. 5 in the House of Commons and Dec. 10 in the House of Lords. If both approve the agreement with Peking, Prime Minister Margaret Thatcher will go to the Chinese capital Dec. 18 to sign it. Ratification by Britain is expected to follow in mid-1985.

The agreement outlines plans for the transition between 1985 and the end of British colonial rule in Hong Kong in 1997, and contains guarantees by Peking that Hong Kong's civil and commercial freedoms will remain relatively unchanged for 50 years once Peking assumes sovereignty over the 400-square-mile territory.

The assessment office is to be a vehicle by which Hong Kong's 5.5 million residents can voice their opinions on its future as a "special administrative region" of China after 1997. But it has been widely criticized in Hong Kong and Britain by those who preferred the idea of a general referendum, or feared that the assessment office's procedure -- it simply invited submissions from any individual or firmup in Hong Kong and reviewed public submissions through the local press -- ignored the views of a silent majority.

Critics also said that since British Foreign Secretary Geoffrey Howe had stated firmly in September that the agreement could not be modified and must be reviewed as a whole, most Hong Kong residents would regard submitting their views as futile.

The leaders of the monitoring team, Patrick Nairne and Judge Simon Li Fook-Sean, criticized the assessment operation in their own report for not guaranteeing confidentiality of submitters' names until several weeks into the exercise.

The office received 3,557 submissions, including 1,815 individual letters, 679 comments from formal organizations or informal groups, and 1,063 views monitored indirectly through the press.

The monitoring team summarized the doubts expressed by Hong Kong residents about their future under a Communist government.

"In brief their message is this: nobody in Hong Kong can escape the uncertainties of the future," it said. "Those who have, or can acquire, a 'right of abode' elsewhere will take personal precautions in the short term while hoping for the best in Hong Kong in the long term.

"The minority who reject the draft agreement do so either because they can never accept reunification with Communist China or because they are bitter about the consequences for themselves as British Dependent Territories citizens."

"The majority who accept it do so chiefly because they regard reunification as inevitable and are relieved that the terms of the draft agreement are as good as they are," the monitors said. "But the verdict of acceptance implies neither positive enthusiasm nor passive acquiescence. The response to the assessment office has demonstrated the realism of the people of Hong Kong. They know that their future now lies in their own hands."

Non-civil servant members of Hong Kong's legislative and executive councils went to London this week with a statement for British leaders summarizing local worries.

Among these were anxiety about interference in Hong Kong's affairs by Peking, fears about the protection of civil rights, uncertainty about the acceptance overseas of post-1997 travel documents, and fears about the presence of Communist troops in Hong Kong.