Abstract： Objective To study serum level of prostate specific antigen (PSA) by age and its relationship with positive prostatic biopsy.Methods A total of 8818 adults who underwent PSA scanning at Health Chek-up Center of Beijing Hospital during July 2009 and July 2010 were retrospectively studied,40 of whom performed prostatic biopsy.Linear regression was used to assess the relation of PSA with age,while Chi-square test was used to compare positive prostatic biopsy in different PSA groups.Results Serum PSA of more than 4 μg/L was more commonly seen in the elderly group (40 ～ year-old group 1.4％,50 ～ yearold group 1.9％,60 ～ year-old group 9.2％,70 ～ year-old group 15.5％,80 year-old group 17％ ; P ＜0.001 ; RR =0.196).In those whose PSA was ＞ 20 μg/L,6 (83.3 ％) were found to have positive prostatic biopsy; and the figure was 10 (50.0％) or 24 (24.0％) when PSA was ＜4 μg/L or 4-10 μg/L group (P =0.048).Conclusions Age was positively correlated with PSA,although no linear correlation was confirmed.Higher serum PSA level (＞ 4 μg/L) may be more common in elderly people and those with a positive prostatic biopsy.