Based on a study of the Early Cambrian paleoecology and an analysis of the community habitat type, the Early Cambrian sea-level change and paleo-geographical evolution in the study area are suggested and the Early Cambrian ecologic system is divided into eight stages in this paper. The authors establish the Early Cambrian ecostratigraphic system of the study area, which contains twenty-three community zones and eleven community Formations. Besides the distribution, composition , ecologic environment evolution and top and bottom boundary lines of these community Formations are expounded in this paper. According to a paleobiogeographical analysis, the Yangjiaping area on the southwest margin of the Jianghan basin belonged to a transition region befores the early Canglangpu stage and to the Yangtze region from the late Canglangpu stage on.