The purpose of prostate cancer staging is to guide the selection of treatment and evaluate the prognosis. The staging is clarified by DRE, PSA, number and site of positive puncture biopsies, bone scan, CT, MRI, and lymph node dissection. 1.T-stage indicates the local condition of the primary tumor, which is mainly determined by DRE and MRI. The number and site of positive prostate puncture biopsy, pathological grading of the tumor and PSA can assist in staging. 2.N stage indicates the lymph node situation, only through lymph node dissection can we get an accurate picture of lymph node metastasis. n stage is important for patients who are ready for radical therapy, the chance of lymph node metastasis is less than 10% for patients with stage below T2, PSA <20ng/ml and Gleason score <6. 3, M staging is mainly for skeletal metastasis, bone scan, MRI and X-ray are the main examination methods. Especially for patients with poor pathological differentiation (Gleason score >7) or PSA >20ng/ml, bone scan examination should be routinely performed.