A client server system includes a server apparatus, and a client terminal apparatus connecting with the server apparatus via a wireless network based on regular connection information, and the client terminal apparatus includes a storage unit to store the regular connection information, a wired transmission unit to transmit temporary connection information to the server apparatus by a wired transmission at a predetermined timing, a wireless receiving unit to receive the regular connection information which is transmitted from the server apparatus based on the temporary connection information via the wireless network, and a storage control unit to store the regular connection information in the storage unit, and the server apparatus includes a wired receiving unit to receive the temporary connection information, and a wireless transmission unit to transmit the regular connection information to the client terminal apparatus, by using the temporary connection information via the wireless network.