A two-wheeled vehicle which includes a two-wheeled vehicle body, a front wheel and a rear wheel respectively rotatably installed at a front and a rear of the two-wheeled vehicle body, and a steering system steering the front wheel is disclosed. The two-wheeled vehicle includes auxiliary wheels connected to the front wheel on both sides of the two-wheeled vehicle body and steered together with the front wheel by the steering system, lifting devices configured to adjust distances of the auxiliary wheels from the ground, and gap adjusting devices configured to adjust lateral gaps of the auxiliary wheels from the two-wheeled vehicle body. The auxiliary wheels are spaced apart from the ground while traveling straight. And an inclination of the two-wheeled vehicle body while turning is limited as one of the auxiliary wheels comes into contact with the ground.