Abstract: The halogenfree flame retardant ethylenevinyl acetate (EVA) composites were prepared by using surfacemodified aluminum hydroxide (ATH) as a flame retardant and linear lowdensity polyethylene grafting copolymer as a compatibilizer, and their structure, flameretardant performance and mechanical properties were characterized by scanning electron microcopy, dynamic mechanical analysis, limiting oxygen index and vertical burning experiment. Furthermore, the effects of the surface treatment and compatibilizer on the dispersion of ATH in the EVA matrix and the interfacial compatibility between ATH and EVA were investigated. The results indicated that a combination of the surface treatment and compatibilizer effectively improved the interface adhesion between the matrix and ATH. Moreover, the smaller the ATH size, the better the flameretardant performance of the composites.