The Lonar crater situated in Buldana District, Maharashtra is natural hyper saline lake formed by hypervelocity meteoritic impact in basaltic rock. An attempt has been made to evaluate physicochemical qualities of Lonar Lake water. A total of 36 water samples were analyzed in 2008 for seasonal variation in physicochemical qualities of Lonar lake water and revealed that, the water is alkaline (pH 10.3) and characterized by high concentration of Salts (9060mg/L), Chloride (3492 mg/L), Salinity (6391 mg/L), Alkalinity (3751 mg/L), Total hardness (480 mg/L), Calcium hardness (118 mg/L), Magnesium hardness (361 mg/L), Sulphate (21 mg/L), Phosphate (0.44 mg/L) and Nitrate (3.7 mg/L), and Dissolved Oxygen (0.0034 mg/L). The data indicated that the alkalinity is increased in monsoon and post-monsoon season while decrease in pre-monsoon season. Likewise the chloride and salinity is increased in pre monsoon season while decreased in monsoon and post-monsoon season. As the Lonar Lake is unique in the world for its alkalinity and salinity of the water but its alkalinity, pH and salinity goes on decrease day by day. Hence this World heritage should be preserved for its alkalinity and salinity