Kolleru Lake, India's largest freshwater body, it is situated between 81º 04' 23" to 81º 24' 53" latitude and 16º 32' 03" to 16º 46' 49" longitude. In 2002 the Kolleru Lake was designated as a Ramsar site and undergone tremendous changes in the water quality due to the development of aquaculture. Kolleru lake is one of Asia's largest freshwater lakes, situated between the Godavari and the Krishna river basins. The main objective of this study is to evaluate Physico-chemical parameters to determine the water quality criteria in kolleru lake. Water samples were colleted from the 10 sampling location during the period of pre and post monsoon (August 2017 to March 2018). The sampling points are selected on the basis of inlets of the lake, lake points, outlet of the lake and based on the aquaculture growth of Kolleru Lake. Total 11 water quality parameters were evaluated during the study period such as pH, TEMPERATURE, EC, TDS, TSS, TOTAL ALAKLINITY, TOTAL HARDNESS, DISSOLVED OXYGEN, SALINITY, COD, and NITRATES. Parameters were estimated by using standard protocol of APHA 2012 and spectrophotometer. All the calculated concentrations of water quality parameters in studied sampling sites showed variations. The spatial distribution maps of water quality were generated for post and pre-monsoon data using IDW spatial distribution method. Water quality standard criteria most of the level parameters measured suggesting the physic- chemical environment still were still not in line with sustainable conservation of the protected area and it was polluted by aquacultural inputs, industrial inputs, agricultural wastes and domestic sewage from neighboring villages .There is a necessary need of regulating, monitoring and protecting of important freshwater ecosystem-kolleru lake.