Researcher Beijing Observatory, 1963. Director Beijing Astrophysical Center, since 1998. Director, department astronomy Peking University, head, department astronomy.
Member academic degree committee State Council. Member Expert Grp. for Post-doctorates, Personnel Ministry. Member selection committee Shaw Prize, 2005—2007.
Member national committee 8th Chinese People's Republic Political Conservative, 1993—1998. Member Central Committee, standing committee 11th Chinese Peasants and Workers Democratic, since 1995. Vice-chairman, municipal committee, Beijing Municipality Chinese Peasants and Workers Democratic Party, since 1997.
Member standing committee 9th National People's Congress, 1998—2003. Vice-chairman municipal committee Chinese People's Republic Political Conservative, since 2002. Member 10th standing committee National People's Congress, since 2003, member, Education, Science, Culture and Health Committee, since 2003.
Fellow: Chinese Academy Sciences (deputy director, academic division mathematics & physics 1998—2002, chairman astronomical advisory board).