Objective To explore the correlation between metabolic syndrome (MS)and benign prostatic hyperplasia (BPH) and the drug treatment of BPH.Methods 300 cases of BPH patients treated between May 2011 to June 2012 in our hospital and Tong-Hai County hospitals of traditional Chinese medicine were included.The patients were divided into observing group (n=100) and control group (n=200).The observing group was treated with 5-alpha reductase inhibitors (finasteride).100 patients in control group-1 were treated with alpha-1 receptor blockers (terazosin).100 patients in control group-2 were treated with finasteride and terazosin.The changes of symptom scores,maximum urinary flow rate and prostate volume at month 3,month 6 and at end of a year after the treatment were compared among all groups.Results In 300 cases of BPH patients,there are 256 cases (85.3％) of MS+BPH,and 44 cases (14.7％) of simple BPH,with no statistically significant difference between the two groups in age and total cholesterol level (both P＞0.05).Among 256 cases of MS+ BPH,127 cases (49.6％) had diabetes,174cases (68.0％) had hypertension,85 cases (33.2 ％) had hypercholesterolemia or high triglyceride.The body mass index,blood pressure,fasting plasma glucose,IPSS gland volume were significantly higher (P＜0.05),and the maximum urinary flow rate was significantly lower in MS+BPH group than in the pure BPH group (P＜0.05).Prostate volume was positively correlated with age,body mass index,systolic blood pressure,fasting plasma glucose.IPSS score were positively correlated with age,body mass index,fasting blood glucose,total cholesterol.Maximum urinary flow rate were negatively correlated with age,fasting glucose,total cholesterol.At month 3 after treatment,the symptom score,maximum urinary flow rate were better in both of control group 1 and 2 than in the observation group (both P＜0.05).At 6 months after treatment,there was no statistically significant difference between the two groups in the symptom score,maximum urinary flow rate (both P＞0.05),while prostate volume was smaller in the observation group than in controls group 1 (P＜0.05).After a year of treatment,there were statistically significant differences in above indicators between the observe group and control group-1 (all P＜0.05),and had no statistically significant difference between the observe group and control group 2(all P＞0.05).Conclusions Most patients with BPH are suffering from MS at the same time.Body mass index,blood pressure,blood sugar,prostate volume,IPSS are higher in MS+BPH patients than in patients only with BPH.MS may affect the incidence and prognosis of BPH.Finasteride combined with terazosin can be used within 6 months,and finasteride can be used alone after 6 months of the drug therapy.