A method and a system for transmitting and receiving Ethernet data to/from a mobile terminal supporting high speed mobility are provided. The method includes: setting a wireless link between a specific access point among a plurality of wireless access points and the mobile terminal and registering identification information of the mobile terminal in the specific access point; allowing the specific access point to transmit an upward Ethernet frame received from the mobile terminal through the wireless link to the service node through the multicast tunnel connected to the specific access point; allowing the service node to recognize whether the mobile terminal is moving and to recognize a multicast tunnel address and identification information of the mobile terminal; allowing the service node to transmit the upward Ethernet frame to an external terminal, receive a downward Ethernet frame corresponding to a response to the upward Ethernet frame, and transmit the received downward Ethernet frame to the plurality of access points connected to the multicast tunnel; and allowing the specific access point, in which the identification information of the mobile terminal is registered, among the plurality of access points that receive the downward Ethernet frame to transmit the downward Ethernet frame to the mobile terminal. Accordingly, when the mobile terminal moves in a wireless LAN environment in which Ethernet data is transmitted and received to and from the mobile terminal, a soft hand-over in which service is not stopped and is stably maintained is provided.