To provide a polyester-fiber-reinforced rubber article wherein the degradation in strengths and adhesive properties of polyester fibers is inhibited by molding and vulcanizing a rubber compsn. contg. a specified amt. of a maleimide vulcanizing agent.

This rubber article is prepd. by molding and vulcanizing a rubber compsn. contg. 1.0-5.0 phr N,N-m-phenylenedimaleimide as the vulcanizing agent. Pref., the compsn. does not contain a linear satd. fatty acid soap as an emulsifier for a rubber component, a post-added linear satd. fatty acid soap as a plasticizer or softener or mold release agent, and an amine as an antioxidant or accelerator. Pref., the compsn. is based on at least one rubber selected from among natural rubbers, styrene-butadiene rubbers(SBR), butadiene rubbers(BR), acrylonitrile-butadiene rubbers(NBR), etc.