Abstract: A chain wheel comprises a chain wheel body formed with a plurality of combining holes for assembly a crank of a bicycle and a plurality of through holes for riveting so that the chain can be engaged with different chain wheel body for speed change; the chain wheel body including an outer periphery and an inner periphery; the outer periphery being formed with a teeth portion with a plurality of tooth for engaging with a chain; a coarse portion formed at a back surface of the chain wheel body; and a combining portion covering upon a part of the outer periphery and both at the front surface and back surface of the chain wheel body; the combining portion being extended through the inner periphery so as to be combined as an integral body at both the front surface and back surface of the chain wheel body.