Abstract:By using the data of FY series satellites, Doppler radar, lightning detection, automatic weather stations, etc., a primary observation and synoptic analysis were made to a lightning stroke casualty event occurring at Kaixian County of Chongqing Municipality on May 23, 2007. The main results show that this event was related to a rapidly developing MαCS which formed in northeastern Sichuan Province in the morning. The lightning stroke event happened when the MαCS moved eastward, developed continually and entered northern Chongqing in the late afternoon. The MαCS eventually developed into a MCC in the evening. The MαCS evolving process was monitored by the FY-2C, FY-2D satellites clearly, but not effectively by radar due to the limitation of detective range regardless of some information it revealed. The observation of the lightning location systems shows that more frequent positive cloud to ground (+CG) strokes were concentrated on the initial stage of MαCS, also the +CG strokes often occurred around the -CG stroke area during the developing stage, this distribution of CG flashes is maybe ralated to the newly developing cells. The southwest vortex and cold air and their interaction are the main triggering factors. The MαCS initiated and developed in weak convective unstable environments, but the middle lower tropospheric air is near saturated.