A method is provided for registering a mobile router in an Internet Protocol version 6 over Low power Wireless Personal Area Network (6LoWPAN) network. The mobile router detects movement into a wireless network through the reception of a beacon message, and sends a Router Solicitation (RS) message requesting registration in the wireless network to a gateway. The gateway acquires an address of the mobile router from the RS message, stores the acquired address, assigns a new address to be used in the wireless network to the mobile router, and sends a Router Advertisement (RA) message with assigned address information and gateway address information, to the mobile router. The mobile router acquires the assigned address information and the gateway address information from the RA message.