Abstract： Objective To Analyze the urodynamic features in the patients with benign prostatic hyperplasia (BPH) complicated with diabetes mellitus (DM) and its diagnostic value.Methods One hundred and twenty patients with BPH who were hospitalized from January,2014 to August 2016 were recruited as study subjects,of whom 60 patients with BPH complicated with MD were designated as the observation group,and the other 60 patients with simple BPH were designated as the control group.Then,analysis was made on the urodynamic test results in the two groups.Results The scores of detrusor dysfunction for the observation group and the control group were respectively 46.67％ and 21.67％,and the percentages of high compliance bladder were respectively 40％ and 18.33％,while the scores of detrusor damage for the 2 groups were respectively 56.67％ and 33.33％.Statistical significance could be seen when comparisons were made between the 2 groups (x2 =18.865,P =0.037;x2 =19.458,P =0.043;x2 =18.382,P =0.041).The percentages of urinary bladder outlet obstruction were respectively 75.00％ and 48.33％,and the percentages of detrusor instability were respectively 51.67％ and 41.67％,also with statistical significance (x2 =5.253,P =0.031;x2 =4.963,P =0.026).Initial precipitant urination volumes for the observation group and the control group were respectively (242 + 15.46) ml and (146 + 22.34) ml,maximum bladder capacity for the 2 groups were respectively (306 +44.52) ml and (226 + 22.73) ml,residual urine volumes were respectively (166.18 + 23.35) and ml (56 ± 12.31) ml,precipitant urination pressures at maximum urinary flow were respectively (26.46 + 9.64) cmil20(1 cmil20 =0.098 kPa) and (61.73 + 11.75) cmH20,the scores of bladder compliance for the 2 group were respectively (47.36 +4.68) ml/cmH20 and (23.26 + 5.37) mL/cmH2O,and maximum urinary flow rate (Qmax) for the 2 groups were respectively (4.12 + 2.12) ml/s and (8.78 +2.36) mL/s.Statistical significance could also be seen when comparisons were made between the 2 groups (t =2.235,P=0.016;t=2.183;P =0.045;t =2.275;P=0.038;t =2.258;P =0.042;t =2.465;P=0.033;t =2.472;P =0.032).Conclusions In the patients with BPH complicated with DM,bladder detrusor dysfunction was severer as compared with those with simple BPH.Early urodynamic detection should be performed for those patients with BPH complicated DM,so as to provide clinical evidence for the selection of treatment methods.