Objective To study the reliability of Gleason score by prostate biopsy with prostatic cancer(PCa)in prediction of tumor location and analyse related influencing factors of positive surgical margins after radical prostatectomy.Methods The retrospective study recruited 72 patients with PCa who had been diagnosed by trans rectal ultrasound-guided prostate biopsy,and eventually treated with laparoscopic radical prostatectomy.The correlation of each index were analyzed by statistical software.Results In this study,Kappa test indicated a good agreement that Gleason score between prostate biopsy and radical prostatectomy.Biopsy positive more focused on four peripheral points near the bottom.Biopsy tumor location was not suitable for predicting tumor distribution.Biopsy Gleason score and biopsy positive percentage in biopsy specimen were independent predictors of positive surgical margins.F and L points had good correlation with the positive surgical margins.Conclusion The biopsy Gleason score is a good evidence to pathological grading in patients.These information will lead to positive surgical margins rise possibly:needle biopsy Gleason score exceed 7.25,positive biopsy percentage more than 45% and the location positive biopsy close to prostate apex.