objective To explore the relationship between metabolic syndrome(MS) and benign prostatic hyperplasia(BPH) in elderly men. Methods  From May 2015 to February 2016, 350 cases of elderly men in the medical examination center of our hospital were collected. Age，blood pressure ,past history and the international prostate symptom score (IPSS) were recorded. Plasma glucose,triglyceride,high density lipoprotein,prostate specific antigen(PSA) ，prostatic volume，and Qmax were measured. The morbidty and severity of BPH were compared. Results  Three hundred and fithy men were enrolled，and were divided into 2 groups:MS group(n=100) and non-MS group (n=250 ).Compared with the non-MS group，the morbidity of BPH was higher in the MS group. There were significant differences in the IPSS，prostate volume and PSA between the MS and non-MS group(P<0.05)，but there was no difference in  Qmax between these two groups（P=0.057).Conclusions There is higher morbidity of BPH in MS patient. MS can increase IPSS and prostate volume，and reduce PSA in BPH ptaiant.Obesity, hyperlipemia and diabetes mellitus are risk factors of BPH. MS should be considered when treating BPH .