Flesibilizer SEBS-g-MAH was used to prepare the system of PA1111/SEBS-g-MAH,and the mechanical and microcosmic properties were studied.The result indicated that the notched izod impact strength enhanced obviously with the increase of toughening agent.When the content of SEBS-g-MAH was up to 25%,the notched izod impact strength is 39.4 kJ/m2,which is 11.3 times of that of pure PA1111.Microstructure showed that the fracture of PA1111 belonged to ductile.There was the phenomenon of stress whitening on the cros...