For this experiment frist the fermented Soybean Meju was prepared by domestic ordinary method of Korean and concentrated Meju suspensoidal extract was made for toxicological test sample on mice and rat. Even the oral dose of 10g extract per kg of mice had not any acute toxicity. So the median lethal dose(LOD50) is lilely to be much greatr or not to be. In comparison of the average weight gain rate for 4 weeks the control and test groups of 0.308g Ex/rat kg and 9.24g Ex/rat kg daily were the much the same as about 19% but 3.08g Ex/rat kg group waas exceptionally 2.7% higher than control For this period all test groups did not show any abnormality in appearance and anatomic findings. In serum GPT GOT alkaline phosphatase and blood urea nitrogen value there were no difference significantly between control and the test groups of 0.308g/rat kg and 3.08g/rat kg but 9.24g/rat kg group was some what higher than control. Especially in cholesterol alkaline phosphatase and blood urea nitrogen value 9.24g/rat kg group or 28days had 100mg/이 37.5u 32mg/이 respectively which were increased significantly. The pathological findings of all test groups especially 9.24g/kg group did not showed any characterized sign of acute or subacute liver damage or intestine lesion. So it is supposed that there is not any tocixants originated from some molds in fermented Korean domestic Meju which is prepared traditionally in winter.