Abstract:The sounding balloon drift data of 119 stations in China from April 2003 to August 2008 are analyzed in this paper. The results show that the drift distance is much longer in winter than in summer in each level. Usually, the drift distance increases with the rising of the sounding balloon. But in summer, because of the change of wind direction, the drift distance will decrease with sounding height increasing. The standard deviation of drift distance also increases with sounding balloon ascent. The distribution of standard deviation is consistent with the drift distance. In winter, the balloons over most of the stations flow eastward. However, the drift direction is much more complicated in summer. In the lower troposphere, the drift direction in all stations is basically eastward, but in the upper troposphere and stratosphere, the drift direction is eastward in northern China and westward in southern China.