Long received his BA degree in British and American literature from Guizhou University in 1965, and conducted postgraduate studies in economics at the London School of Economics from 1973 to 1974.
He joined the Ministry of Foreign Trade and Economic Cooperation (MOFTEC) in 1965, and from 1978 to 1980 served as a diplomat in China’s mission to the United Nations in New York. For the next six years he worked in the United Nations Development Program (UNDP), first in its New York headquarters and then in the Democratic People’s Republic of Korea, serving as the deputy resident representative of the UNDP Office.
After eight years of diplomatic service abroad, Long returned to China in 1986 and became deputy director of the China International Center for Economic and Technical Exchanges (CICETE). In January 1992, Long was appointed director of the Department of International Relations, MOFTEC, and assistant minister of the Ministry in April 1994; three years later, he was named vice minister and the chief representative for trade negotiations of MOFTEC. As the chief negotiator for China’s resumption of GATT contracting party status and its accession to the World Trade Organization, Long dedicated over ten years to this prolonged negotiation to bring China into the global trading system. Apart from trade negotiations, Long was also in charge of multilateral economic and trade affairs between China and the United Nations development agencies. He was fully involved in APEC affairs and attended the APEC meetings of trade ministers each year from 1992–2001. Long has also been active in promoting regional economic cooperation. He was involved in creating the Regional Economic Development Cooperation Committee of the Tumen River Area in Northeast Asia and chaired the committee’s first ministerial meeting in Beijing in April 1996.