Abstract: The characteristics of structure and optimum design of the hardware and software of the measuring and controlling meter based on a new type micro-controller AT89S8252 were introduced briefly in this paper, which was used in agricultural facilities. The design method and the design characteristic of hardware, software and interface of serial communication between microcontroller and computer station in this system were introduced emphatically. The excellent design method enables it to become practicable to popularize the autocontrol system in the group of agricultural facilities.