An Ethernet-based image transmitting/receiving system including a image transmitting device configured to generate and transmit a packet including at least one multiplexed signal of a luminance signal and a chrominance signal; an image receiving device configured to receive the packet, extract the luminance signal and the chrominance signal from the multiplexed signal of the packet, store the luminance signal and the chrominance signal, and output the luminance signal and the chrominance signal by synchronizing lines with each other based on the synchronization information; and an Ethernet cable configured to connect the image transmitting device to the image receiving device and transmit the packet.