Through the analysis of influence of a typhoonand meso-scale vortex in Inner-Mongdia irrigation area of Yellow River on rainstorm the northof Shaanxi,the results are as follows: The vertical structureof convergence-divergencefromlow-level troposphere to high level and unstable air in Hetaolow eddy provide advantageous conditions for developmentand maintenance of upward current near rainstormarea.The vapour and energy channel formed east-ward wind current on the north side of low-pressure circulation of low-level tynoon product the severe vapour convergence in North Shaanxi and result in the accumu lation and release of unstable energy that directly cause the rainstorm far from tynoon.The rainstorm forming is closely related to the mesoscale convergence system in surface stream field and meso-β-scale convective system in satellite cloud picture.