Many vertical sections of Mesoscale Convective System (MCS) detected by CloudSat satellite in regions of high humidity have a structural trait whereby the equivalent potential temperature is close to uniform in the vertical. This is called the moist neutral stratification, commonly found in East Asia in low or medium-high latitudes, over land or sea. Further information regarding the centroid distribution of MCSs was obtained from geostationary satellite cloud infrared image, and the NCEP reanalysis data was used to diagnose some profiles of atmospheric parameters over the centroid of the MCSs. The statistical results show that a moist neutral stratification structure was common in the MCSs. The role that moist neutral stratification plays in the initiation and development of a MCS is discussed from a kinetic and thermodynamic point of view.