Abstract: Based on the enhanced GMS infrared images (at 1-3 hour intervals) and related conventional data for an area south of 32°N and west of 126°E from June to Septemer 1984-1988, a mesoscale cloud cluster is objectively defined, which brigns severe convective weather in the vicinity of a tropical cyclone having the central maximum wind force at or higher than 17.2 m/s. In addition to it, its characteristics, infrastructures, tracks, associated weather and environmental situation are analyzed, new behaviors of the storm are revealed and applicable results for use in forecast are foud.