[1] Qin was appointed as the deputy permanent representative and counselor of the Chinese Mission to the United Nations Office at Geneva, Switzerland in 1984, and from 1987 to 1990, he served as the permanent representative, ambassador, and party secretary of the Chinese Mission to the United Nations Office at Vienna, Austria.

From 1990 to 1993, he served as the Director General of the Department of International Organizations and Conferences within the ministry and in 1993, he was appointed as the Assistant Minister of Foreign Affairs.

[1] Qin was appointed as the Permanent Representative of China to the United Nations in July 1995, succeeding Li Zhaoxing.

During his tenure, in January 1997, China vetoed a UN Security Council resolution which would have sent United Nations peacekeeping forces to Guatemala to monitor a peace agreement which bought an end to the Guatemalan Civil War due to the Guatemalan government inviting Taiwanese officials to the peace ceremony and Taiwan's diplomatic ties with Guatemala.

[1] When 11 countries which had diplomatic ties with Taiwan endorsed Taiwan's bid to the United Nations on 24 July 1998, Qin wrote a letter to then United Nations Secretary General Kofi Annan where he criticized the countries for their "brazen attempt [...] at splitting a sovereign state".