A method and system for communication between wireless networks connected through a wired network in a coordinator-based wireless network environment are provided. According to the method for communication, a wired/wireless relay device that attempts to associate with an initial coordinator-based wireless network notifies a coordinator of information indicating that it acts as a relay device. The coordinator sends the information to wireless network devices within an appropriate coordinator-based wireless network, and each of the wireless network devices transmits data to be transmitted to a device within a different coordinator-based wireless network to the relay device. When the relay device sends the data to a relay device in a coordinator-based wireless network a destination wireless network device belongs to through a wired network, the relay device in the same coordinator-based wireless network as the destination wireless network device sends the data to the destination wireless network device.