A method for reducing power consumption in an Ethernet switch is provided. The method includes: checking a state of packet data input through each of connection ports; detecting a connection port which has a packet rate lower than a predetermined reference value based on a result of the checking; and generating a data transfer control frame with respect to the connection port having the low packet rate and transmitting the generated data transfer control frame to an Ethernet apparatus connected to the corresponding connection port. Accordingly, a transmission line between the Ethernet switch and an Ethernet apparatus having the low to transmission rate is maintained in a low-power state, thereby reducing energy consumption in both Ethernet apparatuses.