A unique compression molding process was investigated to fabricate the high temperature polyimide/carbon composites. To effectively remove the volatiles which have been produced from the polyamic acid formation reaction at temperatures lower than 23$0^{circ}C$, a 2-step process combining vacuum bagging and compression molding was applied. The effects of surface treating(sizing) agent of carbon fiber on the composite property were evaluated in relation to the existence of surface treating agent of carbon fiber. Though the carbon/polyimide composites were processed at high temperatures upto 31$0^{circ}C$, surface treating agent of carbon fiber proved effective without reduction of the composite property