In order to improve interfacial properties of aramid fiber( F-3A) reinforced composites,The fluorination technique was applied to treat the surface of F-3A fiber. The change of the surface structure and chemical composition were characterized by FT-IR,XPS,and SEM analysis,and the composite interfacial properties were evaluated by multifilament property and interlaminar shear strength of NOL rings. The results show:( 1) a mass of micrometer-scaled holes are etched on the surface of F-3A fiber,and abundant ox...