This paper deals with robust stabilization of running self-sustaining two-wheeled vehicle. Recently, some researches about stabilization of two-wheeled vehicle have been reported. These researches have achieved the stabilization running only by the steering control. However, an actual two-wheeled vehicle is running while accompanying stabilization by the rider. We have proposed the stabilization of two-wheeled vehicle in the state of stillness, and have shown the effectiveness. In this research, we compose the control system that aims at the running stabilization of two-wheeled vehicle. We use ℋ∞ mixed sensitivity problem to design the controller to achieve stability running even if the mass of two-wheeled vehicle changes. The experimental results show stability running even if the mass of two-wheeled vehicle changed.