Mesoscale convective systems are very important to Meiyu front heavy rainfall. It is of great significance for improving the forecast capability of Meiyu front heavy rainfall and researches on the structure, development, and physical mechanisms of mesoscale convective systems. In recent years, remarkable advances in the researches on this topic have been reported. A briefly comprehensive review for the advances in the researches on mesoscale convective systems is presented, which include the multiscale structure of Meiyu cloud systems, the development conditions and structures of mesoβ and mesoγ scale systems, the distribution and conversion characteristics of microphysics, and their feedback to dynamical and thermal processes, as well as some related issues.