Abstract: The East China coast is one major cyclogenesis region of extratropical cyclones (ETCs) in boreal winter. In this study, the climatological characteristics of winter ETCs passing over the coastal water of China are analyzed by using clustering and composite analysis. Automated cyclone detection and tracking algorithm are used to identify the ETCs, which are further classified into subgroups according to their trajectory features by using the probabilistic clustering algorithm. Six distinct types of straight moving or recurving trajectories with different climatological characteristics are identified in the clustering analysis. Accordingly, the composite analyses also present six distinct synoptic patterns corresponding to cyclogenesis as well as the impact of ETCs on terrestrial precipitation. The spatio-temporal characteristics of winter ETCs’ origination, movement, and impact are revealed by the clustering and composite analyses.