1968 : Member, Municipal Board, Jorhat.
1968 : Member, Municipal Board, Jorhat.
1971 : Elected to 5th Lok Sabha.
1976 : Joint Secretary, All India Congress Committee.
1977 : Re-elected to 6th Lok Sabha (2nd term).
1983 : Re-elected to 7th Lok Sabha (3rd term).
1983 : Joint Secretary All India Congress Committee (AICC(I)).
1985 : General Secretary, All India Congress Committee (AICC(I).
1986-1990 : President, Pradesh Congress Committee P.C.C.(I)), Assam.
1991-1993 : Union Minister of State (Independent Charge) Ministry of Food.
1993-1995 : Union Minister of State (Independent Charge). Ministry of Food Processing Industry.
1993-1995 : Member, Assam Legislative Assembly.
1997-1998 : Elected as Member of ALA.
1998-99 : Member, Committee on Government Assurances
1998-99 : Member, Committee on External Affairs.
1998-99 : Member, Consultative Committee, Ministry of Petroleum and Natural Gas.
1998 : Re-elected to 12th Lok Sabha (5th term).
1999 : Re-elected to 13th Lok Sabha (6th term).
1999-2000 : Member, Committee on Railways.
18 May 2001 : Assumed the Office of Chief Minister, Assam. (1st Term)
Sept-2001 : Elected as Member of ALA.
11 May 2006 : Elected as Member of ALA.
14 May 2006 : Assumed the Office of Chief Minister, Assam (2nd Term)
13 May 2011 : Elected as Member of ALA.
18 May 2011 : Assumed the Office of Chief Minister, Assam. (3rd Term)