The Greenhouse Temperature Is one of the Key Factors for Controlling the Growth of Crops. Traditional Methods of Temperature Monitoring Can Not Meet the Modern Greenhouse Requirements of High Accuracy, Fast Acquisition and Response. a Greenhouse Temperature Monitoring System Based on MSP430 Was Designed. this System Uses Digital Temperature Sensor DS18B20 to Measure Temperature, MSP430 to Process Data and Transmit Data to the Host Computer through RS485 Bus, Realizing the Real-Time Detection and Long-Distance Transmission of Greenhouse Temperature. this System Has the Features of Simple Structure, Low Power Consumption, Stability and Strong Portability Etc.