Thinning is the preprocessing stage to make easy higher level analysis and recognition for such applications like OCR, Fingerprint classification, Pattern recognition. In this paper we described thinning and its various algorithm. It is concluded that there are some loopholes in thinning algorithm. So there is a need to improve thinning rate. The thinning algorithm’s performance has been analysed in terms of PSNR value, MSE value and thinning rate. To improve performance of the algorithm, enhancement has been proposed which is based on back propagation algorithm. The simulation results shows that proposed algorithm performs batter in terms of PSNR, MSE and thinning rate.