The leaves of Blumea balsamifera DC (Sembong) are traditionally used in conditions related to urolithiasis or kidney stone. The most common kidney stone is the calcium oxalate stone, however uric acid stones can be formed as a mixture of uric acid and calcium oxalate stones. Uric acid production is catalyzed by xanthine oxidase(XO). This enzyme damage of living tissues. Phytochemical investigation on the Blumea balsmifera leaves' extract resulted in the isolation of hydrocarbons, phytosterols and flavonoids. In this study, the inhibition of xanthine oxidase activity by the flavonoids was assessed.