【Objective】 To investigate the pathology change of endometriosis (EMs) rats which were treated by human chorionic gonadotropin (HCG). 【Method】 Twenty-four endometriosis rat models were established and were divided into three groups

then were treated with 258 U/kg (low dose group) and 516 U/kg (high-dose group) of HCG respectively and 0.9% NaCl as a control for 15 days (3 estrous cycles)

the ectopic lesion volume change and endometrium

ectopic endometrium endometrial tissue HE staining changes were investigated. 【Results】 There was no significant difference among the three groups [(208 ± 99) cm3

(219 ± 109) cm3

and (210 ± 124) cm3

respectively] of the ectopic lesion volume (P > 0.05). The ectopic lesion volume of low-dose group and high dose group of HCG [(64 ± 62) cm3 and (54 ± 27) cm3

respectively] were smaller than the control group (203 ± 102) cm3 (P < 0.05). Eutopic endometrium and ectopic endometrial glandular epithelial cells was inhibited state

the performance was as a reduction of the cytoplasm

enrichment of nuclear stain and the nuclear shrink and so on. 【Conclusion】 From histological morphology analysis

HCG treatment in endometriosis rats has a certain effect.