Objectives : The purpose of this study was to investigate effects of extract from mixed culture with Tricholoma matsutake mycelium and Cordyceps militaris mycelium in oriental medicine and cereal midium (OCM) considered effective for the treatment of diabetes. Methods : We examined antioxidant activity and $alpha$-glucosidase inhibit activity of OCM and orally administered OCM extracts to Streptozotocin-induced diabetic ratsat the dose of 100mg/kg, 200mg/kg and 300mg/kg body weight. Results : Total polyphenol content of extracts of OCM was 26.41 mg/g, DPPH radical scavenging activity was 32.24% and SOD-like activity was 31.43%. $alpha$-glucosidase inhibit activity showed 85.3% of acarbose. Blood glucose levels of the OCM extracts-treated groups were lower than those of the diabetic control group (DC), total cholesterol and triglyceride contents were similar to the acarbose-treated group (PC) and ALT, AST were lower than the DC and PC groups. The 300 mg/kg body weight administered group (UM-300) were superior to other OCM-treated groups (UM-100, UM-200). Conclusions : These results showed extract from mixed culture with Tricholoma matsutake mycelium and Cordyceps militaris mycelium in oriental medicine and cereal midium has potentiality to beused in pharmaceutical products and medicinal food for preventive and treatment diabetes mellitus.