A transmission belt adapted for use in a cycle, comprising: a belt body forming a loop that defines an inner space; two spaced-apart mounting axles embedded in said belt body; and a reinforcing unit embedded in said belt body, said reinforcing unit including at least one cord that has a plurality of winding segments and a plurality of connecting segments, said winding segments extending around said mounting axles, each of said connecting segments interconnecting a corresponding pair of said winding segments that respectively extend around said mounting axles; wherein said belt body includes a strip body that has two opposite end surfaces, said mounting axles being respectively disposed adjacent to said end surfaces, said transmission belt further comprising a connecting unit that interconnects said mounting axles so that said strip body forms a loop to define said inner space; wherein said strip body has two opposite side surfaces, and two mounting holes each of which is formed through said side surfaces and permits a respective one of said mounting axles to be disposed therein; wherein each of said mounting axles is configured to be tubular, said connecting unit including two connecting pins that respectively extend through said mounting axles, and a connecting assembly that interconnects said connecting pins; and wherein said strip body further has an inner surface that defines said inner space and that is connected between said side surfaces, and an outer surface that is opposite to said inner surface and that is connected between said side surfaces, wherein said connecting assembly includes two L-shaped connecting plates that are respectively disposed adjacent to said side surfaces and that permit said connecting pins to extend therethrough, and a clip that is engaged with said connecting pin and that abuts against one of said connecting plates, and wherein each of said connecting plates having a connecting section that is disposed adjacent to a respective one of said side surfaces of said strip body, and a wing section that is disposed adjacent to said outer surface of said strip body. a belt body forming a loop that defines an inner space; two spaced-apart mounting axles embedded in said belt body; and a reinforcing unit embedded in said belt body, said reinforcing unit including at least one cord that has a plurality of winding segments and a plurality of connecting segments, said winding segments extending around said mounting axles, each of said connecting segments interconnecting a corresponding pair of said winding segments that respectively extend around said mounting axles; wherein said belt body includes a strip body that has two opposite end surfaces, said mounting axles being respectively disposed adjacent to said end surfaces, said transmission belt further comprising a connecting unit that interconnects said mounting axles so that said strip body forms a loop to define said inner space; wherein said strip body has two opposite side surfaces, and two mounting holes each of which is formed through said side surfaces and permits a respective one of said mounting axles to be disposed therein; wherein each of said mounting axles is configured to be tubular, said connecting unit including two connecting pins that respectively extend through said mounting axles, and a connecting assembly that interconnects said connecting pins; and wherein said strip body further has an inner surface that defines said inner space and that is connected between said side surfaces, and an outer surface that is opposite to said inner surface and that is connected between said side surfaces, wherein said connecting assembly includes two L-shaped connecting plates that are respectively disposed adjacent to said side surfaces and that permit said connecting pins to extend therethrough, and a clip that is engaged with said connecting pin and that abuts against one of said connecting plates, and wherein each of said connecting plates having a connecting section that is disposed adjacent to a respective one of said side surfaces of said strip body, and a wing section that is disposed adjacent to said outer surface of said strip body.