The characteristics of four mesoscale convective systems generated in the eastern Sichuan Province are analysed. The first system was merged from three cloud clusters,and then moved forward rapidly.The second one moved backwark. In the early stage of third system,there were many new convective cells generated continuously in the southwest part of system. Therefore, the system was quasi-stationary. The last system presented cellular structure in the early stage, then it merged with cold front and became a part of the cloud system. All of the four mesoscale convective systems were generated under the condition of the southwest vortex with a warm shear,and their environment flow fields were slightly different.