We attempted to determine the action target of Shiitake mushroom extract with a known anti-hyperlipidemic effect in poloxamer(P) 407-induced hyperlipidemia model. We investigated the anti-hyperlipidemic effects of the water extract from Shiitake mushroom on the progress of high fat diet for 4 weeks. Experimental rats were divided into 5 different experimental groups including an normal group (normal diet; n=10), control group (hyperlipidemia; n=10), Experimental group I (hyperlipidemic rats treated with Shiitake mushroom extract (100 mg/kg, PO), n=10), Experimental group II (hyperlipidemic rats treated with Shiitake mushroom extract (300 mg/kg, PO), n=10), and Experimental group III (hyperlipidemic rats treated with Shiitake mushroom extract (500 mg/kg, PO), n=10). It is to analysis changes in body weight, visceral fat weight, blood lipid profiles, HMG-CoA reductase and histological findings. Body weight and epididymal fat weight was not significantly change in experimental groups (p>0.05). The level of total cholesterol, TG, arthrogenic index, and HMG-CoA reductase were significantly lower in experimental groups than control group (p<0.05). These results suggested that the Shiitake mushroom extract administration may act by inhibitory the release of cholesterol related factors and HMG-CoA from the hepatocyte without liver and kidney cell damage in hyperlipidemia rats.