Environmental estrogens, the major components in the new kinds of environment pollutants, threaten the health of human and animals by its effect on the functions of endocrine system. Microbial degradation is considered as the efficient method in the removal of estrogenic chemicals and the remediation of polluted environment. This paper discusses the well-studied estrogen-degrading microorganisms, compares their degradation products and pathways, then summarizes the proposed microbial degradation mechanisms of estrogens, and finally forecasts the potential research interests in the biodegradation of environmental estrogen.