The non-isothermal crystallization behavior of poly (butylene succinate) (PBS) modified by magnesium hydroxide sulfate whisker (MHSH) was studied by means of differential scanning calorimetry (DSC). Crystallization exotherms were recorded at four different cooling rates, i.e., 5, 10, 15, and 20 degrees C/min. Crystallization parameters were analyzed using Avrami method modified by Jeziomy, Mo models and Friedman's isoconversional method modified by Vyazovkin to evaluate the effective activation energy. Nucleation ability of MHSH was evaluated by employing polarizing optical microscopy (POM). Kinetics studies reveal that MHSH can act as an efficient nucleating agent for the crystallization of PBS. With MHSH addition increasing, the rates of nucleation and growth of PBS are obviously increased. Further analysis of the above models shows that the MHSH does not change the nucleation mechanism and crystal growth of PBS, but decreases the crystallization activation energy of PBS, which facilitates the crystallization of PBS.