In the paper, the Progress in the spatial dynamic city model based on CA (cellular automata) model is reviewed and the new developed CEM model (City Expanding Model in Metropolitan area) with its primary simulation and prediction result in Beijing is introduced. It can be seen that the “bottom-up” dynamic city model based on the individual unit interaction show the last direct of the current spatial city model. At present, it is significant to develop the spatial dynamic city model based on CA and study on the city expanding in metropolitan area in China both in theory and practice.