It was attempted to observe the effect of garlic on the hepatic purine metabolizing enzymes in this study. The activities of adenosine deaminase, guanase, and uricase in rats were not changed significantly following the feeding of 5% garlic juice. Whereas, garlic juice inhibited significantly the hepatic xanthine oxidase activity compared to control group with the lapse of treated-period. The orate level of serum in rats was significantly decreased by the treatment of garlic juice. The above inhibitory effect of garlic was greater in boiled garlic juice than fresh garlic juice-treated group. These results indicated that, according to the chemical properties of allicin which is unstable in heat, other components than allicin in garlic may regulate the hepatic purine metabolizing enzymes.