He was President of the Cambodian People's Party from 1991 to 2015, President of the National Assembly of Cambodia from 1981 to 1998 (Vice President from June to October 1993) and President of the Senate from 1999 to 2015.
Ia menjadi Presiden Partai Rakyat Kamboja dari 1991 sampai 2015, Presiden Majelis Nasional Kamboja dari 1981 sampai 1998 (Wakil Presiden dari Juni sampai Oktober 1993) dan Presiden Senat dari 1999 sampai 2015.