Abstract: The characteristics of 200hPa divergent wind and velocity potential have been analysed for four kinds of tropical cyclones tracks having impact on the south china sea.It is found that the difference of monsoon circulation in 200hPa divergence wind field may affect the medium-range movement characteristic of tropical cyclones tracks.Corresponding to the West Pacific subtropical high,the orientation of 200hPa secondary convergence line and its extension to the west may indicate the variability of track types.The direction of tropical cyclone movement is 2 longitudes west of and parallel to the 200hPa secondary divergence line.