【Abstract】 Objective To study the anti-cancer activities of Z-Leu-Leu-Leu-cho (MG132) against human endometrial carcinoma HEC-1B and Ishikawa cells and the potential of MG132 in human endometrial cancer therapy. Methods HEC-1B and Ishikawa cells were treated with MG132. Cell proliferation was assessed by MTT while cell apoptosis rate and cell-cycle distribution were assessed by flow cytometry. Results The proliferation of HEC-1B and Ishikawa cells was inhibited by MG132 and cell proliferation was significantly inhibited with the raised concentration of MG132 (P