The structure of the GPS anemometric system, performances of the GPS receiver and method to obtain wind field of atmosphere from GPS position information are introduced. Performances of the GPS receiver are relative closely with accuracy of wind field data obtained. To prove the reliability of the GPS anemometric technique, contrast experiments with the wind profiler and Vaisala are carried out. The experimental results show that the correlativity between the wind data of GPS, wind profiler and Vaisala are perfect and profiles of wind speed and wind direction are close too. However, the mean value of wind speed measured by GPS is larger than that measured by wind profiler and Vaisala. It is important to analyze the reason for the differences and to make correction for the GPS method.