Objective To evaluate the value of three-dimensional power Doppler angiography (3D-PDA) in the discrimination between benign and endometrial precancerous lesions in women with bleeding. Methods Sixty-five women with bleeding who examined by 3D-PDA were enrolled. Endometrial volume(V), vascularity index(VI),flow index(FI) and vaseularity flow index(VFI)were measured with the comparison of the final pathology results. The diagnostic value of parameters derived from 3D- PDA was evaluated by using the receiver operating characteristic (ROC) curve.Results The majority of endometrial precancerous lesions in three-dimensional power Doppler angiography ultrasonography were abundant and rich, while endometrial benign lesions in three-dimensional power Doppler angiography ultrasonography were not rich. In benign group, VI, FI and VFI:3.98%?3.42%,21.13?3.15 and 0.643?0.328;in endometrial precancerous lesions group, VI, FI and VFI:5.903%?2.761%,28.964?2.446 and 1.705?0.928 when impulse repeat frequency (PRF) 0.9 MHz;differences of these parameters (VI,FI and VFI)were considered statistically significant between the two groups(P<0.05); differences of these parameters (VI,FI and VFI) were considered statistically significant in differences of PRF, 0.9 MHz/0.6 MHz(P<0.05); the parameters of endometrial volume had no significant differences between two groups;3D-PDA examination sensitivity was 88.9%, and specificity was 100%. the area under ROC curve (AUC) of the meaningful data were 0.851,0.772,0.950 respectively.Among these parameters,VFI had the highest diagnostic value for discriminating benign and endometrial precancerous lesions,the cut-off value of which was 0.81 with a sensitivity of 94.4%and a specificity of 12.8%.Conclusions 3D-PDA is a good diagnostic tool in the discriminations between benign and endometrial precancerous in women with bleeding.