Green microalgae species was collected from Bhavani Lake of Erode in Erode District, Tamilnadu State, India. The Morphological studies were examined by utilizing Fourier Transform Infrared Spectroscopy, Microscope studies, Scanning Electron Microscopic studies and isolated and identified by PCR studies and by these studies that the collected specimen is to be Chlorella sp. In this study to check growth behavior and tolerance of fresh water green algae chlorella sp, under different pH, Temperature, different concentrations of sodium bicarbonate salt, carbon dioxide gas and under different levels of sodium chloride salt.. From the study it is clear that optimum levels of proper carbon source and salinity is very much essential for growing Chorella sp., as they influences its growth rate, biomass and lipid productivity. The experiment aims to analyze the biomass productivity and total lipid content of the microalgae strain under various growth conditions. All the cultures were grown for a period of 10 days. For the growth study reveals that, pH range 4-7, Temperature 26-40, sodium bicarbonate salt concentrations 50-60 mg/l, sodium chloride concentration 0.02, maximum growth rate was observed, when CO2 gas was supplied at 40% concentration, maximum growth and maximum lipid yield of 15 in% dry cell weight were recorded. A highest total lipid content of 20% was obtained.