Objective To investigate the correlation of prostate volume with maximal urinary flow rate and international prostate symptom score( IPSS) in benign prostatic hyperplasia( BPH) patients. Methods 150 cases of benign prostatic hyperplasia admitted to hospital from April,2013 to May,2014 were selected as study objects. All cases were given urodynamic examination,transrectal ultrasound and IPSS. According to Qmax,all patients were divided into group A( Qmax≤10 ml / s,91cases),Group B( Qmax = 11 ~ 15 ml / s,38 c...