Abstract: The microst ructure and mechanical properties were studied for polyamide 66 ( PA66) / ult ra high molecular weight polyethylene ( U HMWPE) blends compatibilized by maleic anhydride high density polyethylene( HDPE-g-MAH) . The result s indicate that the notched izod impact st rength increases obviously with the increase ofcontent of U HMWPE at the expense of tensile/ flexural st rength and modulus. In order to improve the st rength andstiffness of U HMWPE toughening polyamide 66 , short glass fiber (SGF) and inorganic particles were employed toreinforce PA66/ U HMWPE/ HDPE-g-MA H (80/ 20/ 20) . It is found that the tensile/ flexural st rength and tensile/flexural modulus are improved substantially , meanwhile the high notched izod impact strength is maintained , about72.9 % higher than that of PA66.