A series of 3-O-haloacyl allobetulin were synthesized via acylation of allobetulin by haloacetic (trifluro,difluorochloro, trichloro, monochloro) acid in CHCl 3 at 70 °C. The structure of allobetulin was modified at C-3 position, and esters 3a-d were obtained in high yields. Moreover the reactions do not need a catalyst. The structures of all synthesized compounds were confirmed by various spectroscopic methods (IR and NMR) and tested for antioxidant activity.