The hepatoprotective effect of Cordyceps militaris culture broth was determined using HaM/ICR strain mice. Compared to control, the intra-peritoneal injection of benzo($alpha$)pyrene (B($alpha$)P) remarkably increased the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum and the level of lipid peroxide (LPO) in liver tissue, which mean the liver was damaged by B($alpha$)P. However, compared to B($alpha$)P, oral administration of C. militaris culture broth showed decrement of AST, ALT, and LPO activities and increment GST activity and GSH level in liver tissue. These suggest that C. militaris culture broth recovered hepatic damage induced by B($alpha$)P.