A pesticide application monitoring system was designed by using serial communication technology, database technology and VS2008 software programming technology based on MCU STC12C5A60S2. The system could collect information from eight analog sensors and two pulse sensors at the same time. The pesticide application parameter data from sensors (pressure sensor, flow sensor, speed sensor, etc.) would be displayed on LCD monitor, stored in SD card and transmitted to PC through RS232 serial port. Then the data will be stored into database and showed to users in the term of tables and graphs on PC as well. Experiments showed that while the sampling period was 1s, the average measuring accuracy of speed was 97.7% after the system calibration, the average measuring accuracy of pressure in “test-bed experiment” and “sprayer experiment” was 99.3% and 98.7%, and the average measuring accuracy of flow was 99.3%.