Abstract: Polystyrene/polyamide6（PS/PA6）(weight ratio 50/50 ) and polystyrene/polyamide 6/styrene-ethylene/butylene-styrene elastomer grafted with maleic anhydride（PS/PA6/SEBS-g-MA） （weight ratio 50/50/5） blends were prepared through melt blending. The phase morphologies investigated by using scanning electron microscope（SEM）revealed that co-continuous morphologies were formed in both of the blends of PS/PA6（weight ratio 50/50） and PS/PA6/SEBS-g-MA （weight ratio 50/50/5）. But the PS phase and PA6 phase in PS/PA6/SEBS-g-MA （weight ratio 50/50/5）blends became finer than that in PS/PA6（weight ratio 50/50） blends. The non-isothermal crystallization behavior of PA6 in both of the blends was studied with differential scanning calorimetry（DSC）. It was found that the onset temperature（T0）and the peak temperature（Tp） of crystallization shifted to higher temperatures，and the whole-time（∆t）and half-time（t1/2）of crystallization decreased after adding 5% SEBS-g-MA in the PS/PA6 blends. Both the Jeziorny’s method and Mo’s method can describe the non-isothermal crystallization kinetics of both of the blends very well. The Avrami exponent of PS/PA6 blends was from 4.40 to 4.91 and the Avrami exponent of PS/PA6/SEBS-g-MA was from 2.47 to 3.25，and Zc of PS/PA6 blends was smaller than that of PS/PA6/SEBS-g-MA by the Jeziorny’s method. When Xt of PA6 in both of the blends reached the same，lgF（T）of PS/PA6/SEBS-g-MA blends was smaller than that of PS/PA6 blends. These demonstrated that SEBS-g-MA could play a role of heterogeneous nuclei. The Ozawa’s method was not suitable for the non-isothermal crystallization kinetics of PS/PA6 blends and PS/PA6/SEBS-g-MA blends.