Abstract: With acetylated rubber wood as reference, the rubber wood was treated with benzoic anhydride as modifier to investigate the effect of the ratio of benzoic anhydride ethanol reaction solution, benzoylation temperature and acylation time on the dimensional stability of rubber wood. The results show that the ratio of the reaction liquid was 1∶6, acylation for 3 hours at 120 ℃, the maximum volume expansion resistance of the modified rubber wood was 94%, the weight gain rate was 8.12%; the water absorption rate was 10% lower than the material; the contact angle increased to 70.69°, the modification results are better than acetylation modification. Infrared spectrum showed that rubber wood was benzoylated, but the degree of acylation was lower than that of acetylation. The results of SEM showed that the intercellular pores were filled with benzoic acid anhydrides to reduce the porosity. Benzoylation can improve the dimensional stability of rubber wood more effectively than acetylation.