Influences of the concurrent administration of carbon tetrachloride and prednisolone on the biometric, biochemical and histological findings were investigated in male rats prefered twice Sosio-Tang extracts at intervals of 24 hours. Influences of the concurrent admininistration of carbon tetrachlorides and prednisolone twice a week respectively on the findings were also investigated in male rats fed freely diet and. tab water mixed with Sosio-Tang extracts for six weeks. 1. Sosio-Tang extracts. decreased the toxicity of carbon tetrachloride. This was proved by biometric, biochemical and histological findings. 2. Prednisolone increased the toxicity caused by carbon tetrachloride. 3. The group treated with Sosio-Tang extracts. and prednisolon concomitantly increased the toxicity compared with Sosio-Tang extracts. treated group.