Abstract: Resin transfer molding (RTM)characteristics of low mold filling pressure and low mold clamping force provide the opportunity to use altermative RTM mold materials.The thermal characteristics of mold materials influence the temperature profile,resin reaction and tensile strength of the molded composite parts directly.In this Daper,the residual reaction heat and tensile strength were measured for RTM composite parts which were molded from altermative mold materials. The effects of the thermal characteristics of RTM mold materials on composite properties were investigated.