Abstract: A method of manufacturing shoe sole material which is lightweight in addition to having such properties as the conventional rubber sole materials have like wear resistance and elasticity etc., in a simple manner by forming the outsole and midsole layers into one piece by fusion using a mold. The mold comprises mold pieces having on their surface optional pattern and protruding stripes of the same or different pattern carved at equal intervals, and permits a streamline-shaped heel-up on the rear end of the portions which are to become heels, at the same time as forming the midsole and outsole layers into one piece by fusion.