Objective To explore the effect of genistein on proliferation of human endometrial endothelial cells（HEECs）and glandular epithelium.Methods In vitro HEECs and human endometrial cancer-1B cell（HEC-1B）were cultured with 0

1

10

50

100

and 200 μmol/L of genistein alone or indicated concentrations of genistein combined with 0.2 or 1 nmol/L 17β-estradiol（17β-E2）.Cell proliferation was determined by[3H]-thymidine incorporation and cell cycle was measured by flow cytometry.Results After 96 hours of treatment

genistein inhibited the proliferation of HEECs in a dose-dependent manner.The stimulation index reduced from 100%（without genistein treatment）to about 1%（200 μmol/L genistein）.HEECs were arrested at G1/0 and G2/M phase when treated with genistein for 96 hours.When the concentration of genistein was 200 μmol/L

the percentages of HEECs at G1/0

G2/M

and S phase were 96.0%

2.1%

and 1.9%

respectively.However

when HEECs were treated without genistein

the percentages of HEECs at G1/0

G2/M

and S phase were 76.7%

8.5%

and 14.7%

respectively.17β-E2 could not influence the effects of genistein on the proliferation of HEECs.Meanwhile

genistein could suppress the proliferation of HEC-1B.If the stimulation index of HEC-1B was defined as 100% when HEC-1B was treated with different doses of 17β-E2（without genistein）

it was 67%

19%

as well as 32% when cell was supplemented with 200 μmol/L genistein combined with 0

0.2

or 1 nmol/L 17β-E2

respectively.Conclusion Genistein at the concentration of 200 μmol/L can sufficiently inhibit the proliferation of HEECs and endometrial glandular epithelium simultaneously in vitro.