Abstract: Using the ECMWF data, we researched the dynamic structure of the vortex case "01.6.1-5" moving out of the Tibetan Plateau.Conclusionsare obtained as follows:i) In the process of moving eastwardly, the thickness of closed contour or closed cyclonic circumfluence of vortex shows increasing trend with time;ii) In the process of moving eastwardly, in the vertical direction, the "01.6.1-5" shows almost positive vorticity.At 500hpa, positive vorticity displays increasing trend with time.iii) When it is on the plateau, lower-level convergence and upper-level divergence are clearly in the vortex.When it move out of the plateau, lower-level convergence and upper-level divergence are weak in the vortex.iv) When it is on the plateau, in the vortex, the total atmosphere rise.When it move out of the plateau, rising slows down, even sinking usually at middle-low level.v) When it is on the plateau, near the boundary there is always water vapor convergence in the vortex.When it moves out of the plateau, at the lower-level water vapor convergence turns weak, even turns to divergence.While at the area before trough and after ridge, there is lower-level jet, so both water vapor flux and convergence are obvious.