As Chief Secretary, Tsang ranks second to the Chief Executive of Hong Kong Tung Chee Hwa, and advises him on matters of policy and deputises for him during his absence. He is also a member of the Tung's inner cabinet, Executive Council, which is also the highest policy-making body in Hong Kong.
On May 1, 2001, former chief secretary Anson Chan quit the job, citing personal reasons. Tung appointed Tsang to take the deputy leader post and invited the civil service outsider Antony Leung to take the Financial Secretary post.
Before assuming the post as Chief Secretary, Tsang was Financial Secretary. During his six-year tenure, he steered Hong Kong through the Asian financial crisis that swept across the region in 1997 and 1998. He worked with Joseph Yam, chief executive of Hong Kong Monetary Authority defended against the speculators attacking the Hong Kong currency peg.
Tsang joined the civil service in January 1967 and has held many positions ranging from finance, trade to policies relating to the handover of Hong Kong's sovereignty to the People's Republic of China.
As Deputy Secretary of the General Duties Branch between 1985 and 1989, he was responsible for the implementation of the Sino-British Joint Declaration. He became the Director-General of Trade between 1991 and 1993, and was responsible for all facets of trade negotiation and administration affecting Hong Kong. In May 1993, he was promoted to Secretary for the Treasury, responsible for the overall resource allocation, the taxation systems and the cost effectiveness of the Hong Kong government.
In September 1995, he was appointed financial chief, the first Chinese to hold the position. He was awarded the Grand Bauhinia Medal from Hong Kong government in June 2002 and a knighthood (KBE) June 1997 for his long-time service to Hong Kong.
Upon completion of his tertiary education in Hong Kong, he continued his studies in the United States where he completed a Master's degree in Public Administration from Harvard University. He has received honorary doctorates from the Chinese University of Hong Kong and the Hong Kong Polytechnic University.
Mr Tsang is married with two sons. His younger brother, Tsang Yam-pui, was the Police Commissioner of Hong Kong until December 2003, and had been a career policeman who worked up the ranks from inspector.
See also: Politics of Hong Kong