Abstract: The many factors caused data differences of automatic and manual observation were described, including difference of measuring principles and observation method, differences of measuring time and space, difference of sampling mode and algorithm, difference of time level, and so on. Comparison between two objective data of basic meteorological elements, such as air pressure, temperature, wind direction, wind speed, precipitation, humidity etc, was conducted. It is found that observation results of automatic weather station are more objective and scientific than that of manual observation. It has a prominent advantage at an automatic weather station measuring air pressure, temperature, wind direction, wind speed. On measuring rainfall amount, although the automatic weather station has a defect as to provide accumulative rainfall amount, it can provide betimes message of rainfall amount, and so has its superiority on weather forecasting. On humidity measuring, although it cannot get a satisfactory observation in the circumstance of high temperature and high humidity, but it has an advantage in its bounds of moderation.