The study was carried out for the period 1982-1983 to 1999-2000 using the variables like income tax revenue, peak marginal tax rate, GDP at factor cost and GDP at current market price along with time, with and without adjusting for the changes in prices over a period of time. To adjust for price changes the data on Income tax revenue and GDP at factor cost were deflated by using the GDP deflator which was obtained by dividing the gross domestic product at current prices by gross domestic product at constant prices in terms of base year prices (1993-94). The secondary time series data on the variables selected were obtained from Income Tax Office, Coimbatore district; Economic Survey (various issues) published by Ministry of Finance and Economic and Political Weekly (various issues) published by A Sameeksha Trust Publication. Required and relevant tools were applied and results arrived at.