Abstract: Via activating G-protein receptor transduction pathways, nitric oxide(NO)，an important signal molecule, has a complex and diverse role which is closely related with activity and gene expression of nitric oxide synthetase (NOS). NO is involved in tumor related events such as cellular proliferation, migration，especially the angiogenic process, and it is closely related with the occurrence and progression of prostate cancer. NO donors and NOS inhibitors have anti-cancer and radio-chemotherapy enhancement roles.

Key words: Nitric oxide, Nitric oxide synthase, Prostatic neoplasmas, Angiogenesis modulating agents