Objectives : This study was performed to investigate the effects of Rhizoma Arisaematis water extract on lipid and glucose metabolism and histochemical change of obese rats. Methods and materials : 10 rats were divided into normal, control and RA (Rhizoma Arisaematis) groups. We fed the control group a high-fat diet and administered normal saline for 8 weeks. We fed the experimental group of rats a high-fat diet and administered an extract of Rhizoma Arisaematis for 8 weeks. At the end of the experiment, the rats were sacrificed to determine their chemical composition. The groups were examined for effects on blood serum lipids, blood sugar, blood insulin concentration and epididymal fat cells. Results : 1. Serum total cholesterol, triglyceride, HDL-cholesterol and glucose of the RA group decreased compared with those of the control group. These decreased rates were significant(P<0.05). 2. Serum LDL-cholesterol, total lipid, free fatty acid and the average size of epididymal fat cells of the RA group decreased compared with those of the control group. These decreased rates were significant(p<0.01). Conclusions : These results suggest that RA may be used to prevent or cure the obesity iniduced by a high-fat diet.