This study was conducted to investigate the anti-obesity effect of Discorea Japonica Thunb. fermented with Monascus After inducing obesity by feeding hight fat diet (diet induced obesity model: DIO) for four weeks, each 8 rats were assigned to normal (Nor), high fat diet (HF), high fat diet containing orlistat (PC), high fat diet containing different concentration of Discorea Japonica Thunb. fermented with Monascus (UPDM_L, UPDM_H) and Discorea Japonica Thunb. (UPD) extract. Although the UPD, UPDM_L (ultrafine pulverized Discorea Japonica Thunb. fermented with Monascus: 400 mg/kg) and UPDM_H (DIO oral administration ultrafine pulverized Discorea Japonica Thunb. fermented with Monascus: 800 mg/kg) showed weight gain inhibition effects, the results of poor obesity inhibition rather than PC were confirmed. However, it showed a more effective weight loss effect in UPDM_H than UPD, and significantly reduced the weight of epididymal fat and subcutaneous fat. Furthermore, the possibility of anti-obesity effects of Discorea Japonica Thunb. fermented with Monascus can be confirmed by observing the effects of reducing serum total cholesterol, triglyceride and LDL concentrations, reducing ALT and AST levels, and inhibiting fat build-up in liver tissue. It is believed that Discorea Japonica Thunb. fermented with Monascus can be expected to utilize as a functional material that is important to improve anti-obesity and metabolic syndrome.