Abstract: The Mesoscale Convective Complex (MCC) can generate the torrential rainfall in the North China Plain. The composite synoptic environment before MCC genesis is obtained based on three typical MCCs selected from the general investigation of MCCs in the North China plain. Through diagnoses and analysis, the conditions of MCC development over North China plain are investigated. The results reveal that the synoptic environment of MCC development in North China plain is neither the same as in South China nor in North American. Since MCCs often occur at night, the results about the environment and conditions for MCC development are helpful in forecasting whether MCC will occur in the early evening of the day over the North China plain.