To determine whether 17$eta$-estradiol induces the morphological changes in adipose and liver tissues, we measured the effects of 17$eta$-estradiol on adipose tissue mass, adipocyte histology and hepatic lipid accumulation in female ovariectomized (OVX) C57BL/6J mice. Compared to vehicle-treated control mice, 17$eta$-estradiol-treated mice decreased adipose tissue mass and the size of adipocytes, and concomitantly increased the number of adipocytes in a dose-dependent manner. In addition, the administration of 17$eta$-estradiol resulted in reduced hepatic lipid accumulation in a dose-dependent manner. These results suggest that estrogen may regulate adipocyte development and lipid metabolism in female OVX C57BL/6J mice.