Objective To determine the effects of testosterone deprivation therapy on Adiponectin(Adip) level and insulin resistance (IR) in patients with prostate cancer. Methods The levels of fasting plasma glucose(FPG), insulin(ISN), C-peptide(CP), total testosterone(TT), free testosterone(FT), Adip, insulin resistance (HOMA-IR) and quantitative insulin-sensitivity check index(QUICKI) were measured in 32 patients with prostatie carcinoma under castration(CAS group), 30 patients with prostate hypertrophy under total or subtotal prostatectomy (PH group) and 30 age-matched controls (control group). Results The Adip level was lower in CAS group than in control group[ (1.43±0.79)mg/L vs (2.38±0.77)mg/L, P＜0.05)]. HOMA-IR was higher significantly in CAS group than in control group[（1.75±4.84）vs（1.10±3.45）, P＜0.01]. TT was negatively correlated with INS (r = ?0.17; P = 0.043), CP(r = ?0.249, P = 0.32) and HOMA-IR (r = ?0.781; P＜0.01); positively correlated with Adip(r = 0.819, P＜0.01) and QUICKI(r = 0.420, P=0.026). Conclusion Endogenous testosterone deprivation may be involved in development of cardiovascular diseases in males by regulating insulin resistance and Adip level.