This study was performed to find out the detoxication effects of natural products Thuja orientalis, leaf of acorn, aloe ferox mill, pine cone, pine root, lonicerae flos on nickel toxicity. The experimental rats were divided into 3 groups such as nickel alone treatment group, natural products treatment groups before and after nickel treatments. Each group was administered with difference dose of nickel such as 6.6 mg/kg/day, 13.2 mg/kg/day, 19.8 mg/kg/day respectively, for 14 days. Natural products were administered by 400 mg per kilogram body weight rat per day. The weight change of rats, nickel concentration in organs, survival rate of rats, morphology of organs were observed in the experimental groups. The results obtained by the experiment were as follows: 1. The rats in the group treated with natural products had no effect on the weight gain. 2. The mean survival rate of rats in the nickel alone treatment group was 72.5% (6.6 mg/kg/day), 68.9% (13.2 mg/kg/day), 60.2% (19.8 mg/kg/day) respectively. 3. As for the amount of nickel accumulation in organs, it was the lowest amount treated with pine cone, pine root in that order. 4. When kidney and liver tissues were observed with as optical microscope, obvious change were visible in those tissues treated groups with Lonicerae and Aloe.