Two-wheel inverted mobile manipulator does not have casters, which avoid the platform of a mobile robot inclining but have complicated dynamical characteristics. Therefore, this mobile manipulator can realize rapid and smooth motion, but in exchange some control is needed to avoid its platform inclining. Rotating platform is considered as a passive joint, which is not actuated. When robot perform a task in contact with environment, reaction force in end-effector acts on passive joint and platform is made inclining. This paper propose a control method for pushing operation by two-wheel inverted mobile manipulator.