The current investigation was conducted to determine the water quality of river Ganga with respect to physico-chemical parameter of river Ganga seasonally. Ganga is one of the holiest rivers of India. Due to its religious importance and multiple use of river water for human consumption, the water quality of river Ganga are deteriorating rapidly, therefore regular monitoring of river Ganga is essential. With this aim various studied have been conducted in the past on fresh water. The present study deals that the water quality monitoring of river Ganga at Haridwar was considered at different sampling sites during one year period divided in Winter (November-Februrary), summer (March-June) and monsoon (July -October). Parameters studied were pH, Free CO2, D.O., temperature at the spot and other parameters like as acidity, alkalinity, hardness, calcium, chlorides, B.O.D, etc. in the lab. TDS and TSS were recorded maximum in monsoon during our study. The value of dissolved oxygen observed maximum in winter season. During our study period it has been found that the water quality of river Ganga was quite good in all three seasons. However change in seasonal conditions had a great effect on physicochemical parameters.