Abstract: Objective To investigate the focal basal cell layer disruption（FBCLD） in prostate and the integrity of its adjacent basement membrane and their relation with the occurrence and development of prostate cancer. Methods HE,and double P63 and CK34βE12 immnostaining were performed for the selected 25 samples of prostate cancer.The integrity of basal cell layer was observed.Basement membrane was stained with Ⅳ collagen to determine its change. Results Among the 89 FBCLD foci detected in the 25 samples,basement membrane disruption was found in 76（85%）,thinner basement membrane or weak immunostaining was observed in 13（15%）.Positive P63-labelled basal cell layer was thicker than negative P63-labelled basal cell layer when the P63 labelled basal cell layer was normal.Sixty percent of PIN showed FBCLD and basement membrane disruption.The focal disruption in normal and benign tumor tissues was milder. Conclusion FBCLD is closely related with changes in basement membrane.Duct or gland with FBCLD and basement membrane disruption may be a greater risk of developing cancer.