The normal value of total prostate-specific antigen is <4.0 μg/L. Mildly elevated and markedly elevated values suggest the possible presence of benign or malignant prostate disease. Prostate-specific antigen (PSA) is a glycoprotein secreted by the epithelial cells of the prostate ducts, 80% of which exists in serum in bound form, i.e., composite PSA (c-PSA), and 20% exists in free form, known as free PSA (f-PSA), and the sum of the PSA in the serum is total PSA (tPSA). The normal value of tPSA should be <4.0 μg/L, while the normal fPSA should be <0.8 μg/L and the fPSA/tPSA ratio should be >0.25. When tPSA>10μg/L is significantly elevated, suggesting the possible presence of prostate cancer; tPSA at 4~10μg/L may be caused by benign diseases such as prostatic hyperplasia or prostate cancer, or may be caused by operations such as prostate massage, which requires fPSA/tPSA for differential diagnosis, fPSA/tPSA <0.1 suggests that it is possible to be prostate cancer. It is recommended that those who have abnormal total prostate-specific antigen values should consult a doctor for further examination and treatment as prescribed by the doctor.