Abstract: The main factors affecting the quality of upper air sounding was discussed from the practical work in this article, and suggestions were put forward. It showed that radar calibration methods, radar observations of environment, base point resistance of humidity and measuring data accuracy, the accuracy of the instant meteorological elements, etc were all important factors affecting the quality of upper air sounding data. Adopting scientific radar calibration methods, accurately determine station radar detection performance,the base point of resistance,the base value determination and cast instant data automation,the second correction of stations, all these measures would provide technical guarantee to improve the quality of upper air sounding.