Objective To simulate the temperature distribution of multiple electrode bipolar radio-frequency(RF) for global endometrial ablation by finite element method.This thermotherapy might improve the safety and effectiveness of endometrial ablation.Methods With three common sizes of uterine cavity as the research objects and according to the bio-heat transfer equation,three finite element models were established to analyze the changes of peak temperatures,lesion area and lesion depth in different sizes of uterine cavity under different radio-frequency voltages.Results Under the same voltage,as the size of uterine cavity became greater,maximum temperature changed small,minimum temperature and lesion depth became lower,and lesion area was larger.In the same size of uterine cavity,as the power became higher,maximum temperature was higher,and minimum changed small,lesion region was larger and lesion depth was deeper.Conclusions Uterine cavity size and radio-frequency voltage should be considered in endometrial ablation.