With the rapidly development of electron technology, more and more application employ singelchip to design produce. That is, the programmer and simulator become very important in developing of produce based on singelchip. This thesis present mainly the development of programmer and simulator used in singelchip. and introduce the hardware circuit and software design of the programmer and simulator in detail. The simulator has some advantage such as smaller cubage, high ratio of performance VS value, which consist of circuit using double phasic RS232 shift TTL level and data bus driver circuit. Compared with simulator, the programmer own the same feature, adding with only difference lie in that has voltage convert circuit and main control module. According to the test, the designed simulator can finish main work to replace common MCS-51, in addition, it can be also applied for ISP & IAP function producing by ATMEL corporation and by SST corporation, respectively. The programmer can program all chips of AT89 serial, which include encrypting code, reading & writing . The good software interface, perform robust, fast speed are other feature in singelchip.