Based on the evolution of the megalopolis theories and the analyses of population census and statistical yearbook data，this study explores the issues of coordination development of Megalopolis’s population．Based on a clear distinction between the concept of core area and core city，and using methods of spatial autocorrelation and industrial structure deviation analyses for comparing the spatial scale，space structure of population and spatial coordination of industry between Northeast megalopolis in USA and Beijing-Tianjin-Hebei megalopolis in China，this study shows that for a typical megalopolis，its incubation process presents a significant stage development pattern．The population proportion of its core city rises at the beginning，and then declines．The spatial distribution of population shows a changing trend from single pole to multi growth poles．The spatial structure of population has both characteristics of aggregation and dispersion．The adjustment of industrial structure in core region has major implications to the coordination development within Megalopolis．