Abstract: To study the impact of nucleation effect and weak interface interaction of composite materials in the presence of high content of rigid particles on the non-isothermal crystallization behavior of poly(butylene succinate) (PBS), PBS/MCC composites with microcrystalline cellulose (MCC) content of 5wt%-25wt% were prepared by melt blending. The melting behavior and non-isothermal crystallization kinetics of PBS were characterized by differential scanning calorimetry. The crystallization behavior and mechanism of PBS were analyzed using Avrami method modified by Jeziorny and Friedman's isoconversional method modified by Vyazovkin. Kinetics studies reveal that MCC can act as an efficient nucleating agent to increase the crystallization temperature and crystallization rate of PBS, and promote the growth rate of PBS crystals without changing the nucleation mechanism and crystal growth of PBS, but the weak interface interaction between PBS and MCC will significantly inhibit the nucleation ability of PBS and reduce its crystallinity which reduced from 34.8% to 28.8%. The results of this study have certain guiding significance for studying the influence of weak interface interactions on the crystallization behavior of PBS in the presence of high content rigid particles.