Abstract: The two cold vortex position were similar between on July 16,2010 and July 15,2011,but they caused different weather during the cold vortex.The circulation background,physical quantity,satellite image were analyzed,the results showed that： upper cold vortex and low-level mesoscale shear are the main influence systems.Because the lower temperature configuration,the low-level shear in different positions,resulting to the weather are different;severe convective weather area with negative SI index,K index values of area and a large high-value area of CAPE have good relationship;satellite images a convective cumulonimbus smooth edges neat group.