Anti-obesity effect of biocellulose and diet formulation containing it was evaluated using obese rats. Thirty male Sprague-Dawlely (SD) rats were randomly assigned to high-fat diet group (CON), high-fat diet group containing 5% biocellulose (BIO), and high-fat diet group containing 5% dietary formulation (DF). After 10 weeks, body weight gains of BIO and DF groups were reduced by 15.1 and 6%, respectively, as compared with CON group. Epididymus, parirenal, and visceral fat pads of BIO and DF groups were lower than those of CON group. Weight of interscapular brown adipose tissues increased slightly in BIO group and significantly in DF group. Size of adipocyte in rats decreased in BIO and DF groups. Results indicate biocellulose-containing diet has anti-obesity effect by reducing body weight gain and white adipocytes depots in rats fed high-fat diet.