HOXA10 gene plays an essential role in differentiation of the endometrium and in human reproduction. The aim of this study was to investigate the regulatory effect of sex steroids and HB-EGF on HOXA10 gene in Ishikawa cells. Ishikawa cells were incubated with 17-beta estradiol (10(-8) mol/L), medroxyprogesterone acetate (MPA) (10(-6) mol/L), RU486 (10(-5) mol/L) or HB-EGF (10 ng/mL) for 48 h respectively. The expression of HOXA10 gene was detected by immunofluorescence, reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. Our results showed that either estrogen alone, progestin alone or progestin combined with estrogen could significantly increase the expression of HOXA10 gene 48 h after the treatment (P<0.05). But estrogen combined with progestin and RU486 could inhibit the up-regulation by estrogen and progestin. HB-EGF could elevate the expression of HOXA10 gene 48 h after the treatment (P<0.05). It is concluded that both estrogen and progestin can up-regulate the expression of HOXA10 gene in Ishikawa cells, but RU486 can inhibit the effect and HB-EGF can elevate the expression level of HOXA10 gene.