This paper proposes a wheeled walking assistive apparatus that assists a person with hemiparesis. This device has high stability comparing with leg types because its wheels always contact on the ground. In addition the user does not need to support the weight of it. The user wears the device bending his/her hemiplegic knee. Differential gears provided between front wheels enable the user to rotate in the horizontal direction. The gas spring attached on rear wheels enables the user to tilt the device forward easily. We propose the controlling method for this apparatus based on the tilt angle that is measured by a gyro sensor and acceleration sensor when travelling. Results obtained from experiments demonstrate that non-disabled persons can travel stably indoors.