Provided are a communication control system and a mobile station control method for allowing a mobile station to quickly return, upon the termination of a communication performed via a fallback wireless communication system used by the mobile station, to the connection with a base station of a wireless communication system used before the occurrence of the fallback state. An RNC (210) comprises: an information element acquiring unit that acquires, from an LTE system (10), an information element that is used to allow a return to the connection with a base station used before a fallback state; and a mobile station control unit that uses the information element, which is acquired by the information element acquiring unit, to execute a control to allow a mobile station (300) to return to the connection with an HeNB (110). The mobile station control unit executes that control on the basis of a communication state of the mobile station (300) in a 3G system (20).