This paper implements MCS-51 microcontroller embedded Internet connecting technology. The microcontroller communicates with Internet through Ethernet network interface card ATL8019AS. The reduced TCP/IP protocol stack--uIP protocol suit, which is open source code program, drives the bottom network devices. Some application services are realized based on API of uIP. Finally, the thesis provides the electronic circuit and main program of MCU. A monitoring system for parking is realized with the application of MCU embedded Interent.