Water is life” it means that “Jal hi jeevan hai”. All life on earth depends on water. It is nearly three quarters of the weight of a living cell, so the present study deals with comparative analysis of water of Pushkar Lake before, during and after the Pushkar fair. Pushkar lake is very holy and sacred lake situated in Ajmer. Pushkar fair held in kartik month. Seeing its use and significance, the Gau Ghat was selected for study. There are many parameter were studied in order to determine the status of the water of Pushkar lake such as temperature, pH, turbidity, transparency, acidity, alkalinity, biological oxygen demand, COD, dissolved O2, CO2, etc. The decrease in temperature during and after fair may be due to change in the weather. pH shows non-significant change. Acidity and Alkalinity after, during and after fair significantly. Transparency decreases and turbidity increases during fair because of the various religious rituals. Chloride content and salinity are increased during and after fair. Hardness of water increases because of the after effects of the pollution caused during the fair. BOD and COD values increases during fair and return near to values of before fair when the fair is over. Because of aesthetic importance the water of Pushkar Lake is very sacred. Therefore quality of water should be strictly maintained.