Following the start of Cultural Revolution, he was forced to drop out of the institute and work in cadre schools and farms in Shanxi, Jiangxi, Hunan, Hebei and Guangdong Provinces.

[1][2] After being reinstated into the Ministry of Foreign Affairs of the People's Republic of China in 1970, he was assigned as a staff and attaché with the Chinese Embassy in Kenya.

In 1990, he was promoted to Assistant Minister of Foreign Affairs and in 1993, he was appointed as Permanent Representative of China to the United Nations.

On the same month, when asked about the return of the U.S. Navy P-3 Orion surveillance aircraft which made emergency landing on Hainan Island during the Hainan Island incident, he stated that "if we allow such a military plane, which had a mission of spying on China, to be flown back out of China, that will further hurt the dignity and sentiments of the Chinese people."

[1][6][7][8] The National People's Congress appointed Li as the new Minister of Foreign Affairs on 16 March 2003, succeeding Tang Jiaxuan.

When the war began on 20 March, the Chinese Foreign Ministry issued a statement on the "political settlement of the Iraq issue within the UN framework, urging the Iraqi Government to fully and earnestly implement relevant Security Council resolutions and calling for respect for Iraq's sovereignty and territorial integrity by the international community" and "war will inevitably lead to humanitarian disasters and undermine the security, stability and development of the region and the world at large."

On 24 March, in a phone call with Russian Foreign Minister Igor Ivanov, Li appealed for cessation of military operations and expressed concern of the humanitarian catastrophe caused by the war.

During the meeting, Li stated the "Chinese government has never done anything for which it has to apologise to the Japanese people" and "the main problem now is the Japanese government has done a series of things that have hurt the feelings of the Chinese people, on the Taiwan issue, some international issues including human rights and especially in its treatment of history.

[20][5] However, due to his firm stance on the Taiwan issue, coupled with his striking personal image, some people have referred to him as "the minister with a bad temper".

Qin's father served a secretary to former President of China Liu Shaoqi and as head of the Consular Department of the Ministry of Foreign Affairs.