He was a Member of the Assam Legislative Assembly from the Indian National Congress party for Digboi.
[2] Dhanowar was the Indian National Congress candidate for the constituency of Digboi in the 1978 Assam Legislative Assembly Election.
In the 1985 Assam Legislative Assembly election, Dhanowar sought reelection in Digboi.
He was made minister for Excise, Labour and Employment in the first Tarun Gogoi cabinet.
His son, Gautam Dhanowar, was the Indian National Congress candidate for Digboi in 2016 but lost.
His son resigned from the Indian National Congress after being denied the 2021 ticket for Digboi and he later joined BJP.