To provide a method for preparing a belt with gear teeth on both faces wherein accuracy on length of the belt is improved by stabilizing a pitch line of a core line and accurate shapes of the teeth are generated and time for molding can be shortened.

A method for preparing a belt with gear teeth on both faces consists of a premolding process wherein after a laminated body of a gear teeth fabric 5 and an unvulcanized rubber sheet is semi-vulcanized and embossed on the outer peripheral face of a mold with channels, a premolded body is formed by spinning a core wire 6, a vulcanization process wherein a prevulcanized molded body 8 is formed by heating and pressing under a condition where a release paper is wound on the surface of the premolded body, and a final embossing and vulcanization process wherein by heating and pressing a belt-like molded body 9 prepd. by laminating an unvulcanized rubber sheet 4' and a gear teeth fabric 5' on the prevulcanized molded body taken out from the mold with channels in a press mold with the same shapes of gear teeth with a definite pitch on its top and bottom bases, a top gear teeth part is embossed and vulcanized to form the belt with gear teeth on both faces.