A gyro-two-wheel vehicle was designed, realized and experimented which stably stood during not only running but also stopping. A horizon sensor, a servomoter, a perpendicular gyroscope and electronic circuits were used in order to stabilize the vehicle, whose center of gravity was located at higher position than the supporting plane. After the stability condition was derived in the corresponding differential equations, the detailed structure was shown including mechanical feature, control system and horizon sensor. Finally experimental trajectories were shown to confirm the stability of the vehicle.