Abstract: The microcrystalline cellulose(MCC) and poly(butylene succinate) (PBS) composites were prepared by melt blending method. The influence of different temperature and MCC content on the steady-state rheological behavior and dynamic rheological behavior of the composites was studied by advanced capillary rheometer and rotationnal rheometer. The results show that:the rheological behavior of the corresponding relationship between the viscosity and the shear rate of the composites fits the power law model. Arrhenius equation can be employed to describe the dependence of the viscosity on temperature. The storage modulus (G') of the composites keeps invariant in linear viscoelastic region. When strain(γ) is over critical value (γ_c), the composites enter into the nonlinear viscoelastic region and the "Payne effect" occur. The γ_c decrease rapidly with the increase of strain. The storage modulus (G'), loss modulus (G") and complex viscosity(|η^*|) of the composites all increase with the increasing contents of MCC in the range of angular frequency(ω) scanning. The value of G" is always higher than G' and the value of loss factor(tan(δ)) is always greater than one under the condition of the invariable content of MCC. Second plateau is observed for G' at low ω. The study of processing rheological properties of MCC/PBS composites might be valuable for the processing of MCC/PBS composites.