An electric motorcycle includes an electric driving unit including an electric motor and a power transmission mechanism, and is configured to halt supplying of electric power to the electric motor for at least a period in the stopped state. A starting assist method is executed in the electric motorcycle. The starting assist method comprises the steps of activating the electric motor and rotating a rotor by itself to store rotation energy in the rotor, keeping the rotation energy stored in the rotor in the step of storing the rotation energy, in a stopped state of the electric motorcycle, and transmitting the rotation energy of the rotor kept in the step of keeping the rotation energy to the rear wheel as starting assist power.