Design of trial Prospective Randomized Trial Study treatment: Continuing low-Dose aspirin before transrectal prostate biopsy Primary endpoint: The incidence, duration, and severity of bleeding complications Statistical analysis and sample size estimation: Fisher's exact test or chi-square test will be used to explore the differences between two groups for categorical variables, and Student t-test will be used for continuous variables. Under the assumption of a difference of 25% of bleeding complications in each group, with α=0.05 and power=0.80, 60 subject are needed in each arm. Assuming the drop-out rate to be 20%, the targeted recruit number is 150 in total.