Elevated serum prostate-specific antigen (PSA) values due to prostate hyperplasia usually do not exceed 4 ng/ml, and some of them may be up to 10 ng/ml, and those exceeding that are considered to be possible prostate cancer. PSA is a prostate-specific antigen, which is synthesized in both normal and cancerous epithelial cells. Therefore, in prostate hyperplasia, increased serum PSA value can also be detected. The normal value is 0~4ng/ml, the psa value of patients with prostate hyperplasia is usually not more than 4ng/ml, the more normal prostate tissue destruction, the higher the serum PSA value. Between 4~10ng/ml, some patients (about 1/4) suffer from prostate cancer. More than 10ng/ml the risk of developing prostate cancer increases. Generally the larger the tumor load of prostate cancer the higher the psa, and the higher the psa can be up to thousands. Rectal diagnosis of prostate, MRI (magnetic resonance imaging) of prostate, pathology of prostate puncture, serum PSA and other tests are all important for clear diagnosis, serum PSA, if it exceeds 10ng/ml, has significant significance in assisting the clinical diagnosis of prostate cancer, and early diagnosis and treatment is needed.