There are numerous characteristics of females as a higher organism and maintaining appropriate level of estrogen is possibly the most fundamental and important factor for reproductive aged women. Appropriate secretion of estrogen during the reproductive age is indispensable to keep female in healthy condition. In addition to natural menopause and surgical menopause, aberrant secretion of estrogen in reproductive aged women may predispose to increase risk of osteopenia, dyslipidemia and impaired glucose tolerance, and epidemiological studies and experimental data strongly support that estrogen possesses anti-diabetic properties. The function of estrogen in glucose homeostasis can be explained by direct functions of estrogen and by indirect function through estrogen receptors(ERs), although the latter is believed to be mainstream. ERα is believed to be the key ER in brain, pancreatic, liver, muscle, adipose tissues, and macrophages.