The microcrystalline cellulose (MCC) was used for inducing crystallization of the isotactic polybutene-1 (iPB) and the maleic anhydride grafted polybutene-1 (MAPB) was used as a compatibilizer. The crystallization behavior of the composite demonstrated that the addition of MCC could significantly accelerate the crystallization rate of iPB and theaddition of MAPB could improve the compatibility between MCC and iPB. Moreover, the properties of the compositeswith MAPB were better than those without MAPB. The crystal transformation had been completed after storage for 5 days and the form I was formed after storage for 3 days which was faster than pure iPB. The non-isothermal crystallization kinetics data of the composites indicated that the modified Avrami equation could describe the non-isothermal crystallization process of the iPB/MCC composite and the t1/2 of the composites was shortened for 24.32% and 40.27% which indicated that MCC could promote the crystallization of iPB.