Objective To compare the positive rates and complications of ultrasound?guided transperi?neal and transrectal prostate biopsies with 12+X method. Methods From January 2011 to January 2015,252 cases patients underwent ultrasound?guided prostate biopsies with 12+X method for suspected prostate carcinoma were selected as research subjects,including 114 cases were perineal puncture( transperineal group) and 138 ca?ses were transrectal puncture( transrectal group) . The positive rates and complications of biopsy were compared between the two groups. Results The positive rates in the transperineal and transrectal groups were 43. 5%( 50/114) and 41. 3%( 57/138) ,and there was no significant difference( P>0. 05) . No statistically significant differ?ences were observed between the two groups according to different PSA levels(≤4. 0,>4. 0-≤10. 0,>10. 0-≤20. 0,>20. 0 μg/L) ( P>0. 05) . There were no significant differences between two groups in complications such as:hematuria,lower urinary tract symptoms and acute urinary retention( P>0. 05) . The incidence rates of post?biopsy infection and rectal bleeding were remarkably lower(2. 6%(3/114) vs. 13. 0%(18/138),1. 8%( 2/114) vs. 11. 6%( 6/138) ,P=0. 005,0. 002) in transperineal group than in transrectal group. However,the perineal swelling rate was remarkably higher in the transperineal group than that in the transrectal group( 8. 8%( 10/114) vs. 0. 7%( 11/138) ,P=0. 003) . Conclusion Ultrasound?guided transperineal and transrectal pros?tate biopsies with 12+X method are both effective for the diagnosis of prostate carcinoma. The positive rates of the two approaches are similar,but the complications are different. The choice between the two approaches depended on the clinical features of the patients.