The design of Ethernet interface circuit in the Embedded system based on ARM processor LPC2294 is expatiated. Through studying the current hot technology in the domain of Embedded technology，the exploitation and application of the Ethernet technology on the Embedded system are realized. The involved technologies include such as the hardware design of ARM processor, the interface circuitry design of LPC2294 and the Ethernet controller RTL8019AS, UDP protocol of Ethernet transport layer, software design flow of TCP/TP, and the process of system communications debugging are introduced. The ARM processor is connected with RTL8019AS via exterior data bus to have excellent real time and dependability,and the Ethernet function of Embedded system is implemented.