Abstract: This invention relates to a power transmission structure of scooter, in which one rear wheel of the scooter is provided with a power source and the other rear wheel is a free wheel. By the usage of power equipment for driving a single rear wheel, the volume taken by the power equipment is reduced and more space is thus available for accommodation of more power equipments such that both the running distance and running time can be lengthened. As there is no such elongated structure of transmission therein, the power transmission structure has advantages of having sufficient power and power-saving effect so as to achieve cost-saving.