In this study. investigated the effect of shot peening on the corrosion of SAE 5155 steel immersed in $3.5\%$ NaCl solution and corrosion characteristics by the heat treatment during shot peening process. The immersion test was Performed on the four kinds of specimens. Corrosion Potential, polarization curve, residual stress etc. were investigated from experimental results. From these test results, the effect of shot peening on the corrosion was evaluated The important results of the experimental study on the effects of shot peened SAE 5155 on the corrosion are as follows; Shot peened specimens show the low of corrosion current as compared with un peened specimens. In the case of corrosion potential, shot Peened specimen shows more negative Potential as compared with that of parent metal Surface of specimen, which is treated with shot peening Process. is Placed as more activated state against inner parent metal. Corrosion rate is shown that shot Peened specimens have less corrode than un peened specimens. But non heat treated shot peened specimens show the biggest weight loss owing to variable compressive residual stress layer by shot ball.