Abstract: In this work the mechanism of the solid-state polycondensation of crystalline nylon-1010 salt (sebaeodiamonium sebate) with short carbon fiber composites and effects of the chemical and physical interface Letween the fiber and matrix have been studied by the use of a number of techniques including determination of conversion rate and of molecular weight,IR,polarized light microscopy and SEM.The experimental results indicated that during the solid-state polycondensation the invert gas N₂ flow,reaction-temperature and time,amount and surface characteristics of carbon fiber used remarkably influence the conversion rate and molecular weight of the formed nascent nylon 1010 matrix.It was found that some interfacial effects such as fiber surface nucleating tire crystallization and catalytic effect for the "in situ solid-state polycondensation" of nylon1010 salt existed.The interfacial effects of carbon fiber on the expitaxial crystallization of the formed nascent nylon-1010 have been discussed.