simple method to improve the hydrophobicity of microcrystalline cellulose (MCC) through modifica- tion by using soybean oil was developed. The method consists of mixing soybean oil ethanol solution with pretreated MCC and heating at 110◦C. Fourier transform infrared spectroscopy, X-ray diffraction and wettability test were used to characterize the modification of MCC. The results showed that the pretreatment of ultra-fine pulverization significantly enhanced the modification of MCC. The crystalline structure of MCC was not destroyed during the pretreatment and the modification. The modified MCC displayed a higher affinity for low polar solvents such as dichloromethane and toluene.