Urban agglomeration is an important carrier of China's new urbanization strategy, but also a new geographical unit for participating in global competition and international division of labor. At present, the mode of China's regional spatial governance is undergoing a major shift from the original spatial split according to the administrative divisions to govern in accordance with the type of area. Based on the significant extension of the characteristics of urban agglomerations, we divide the 23 Chinese urban agglomerations at four levels and analyze the spatial variation, aiming to provide a scientific basis for the implementation of China's urban agglomerations spatial pattern optimization and planning. First, the 23 areas are divided into national, regional, sub-regional and local levels of urban agglomerations with reference to the development status of more mature urban agglomerations worldwide, resulting in a "3-5-6-9" pyramid structure for the four levels. Then, based on the five essential characteristics of urban agglomerations, we build an index system for the classification of urban agglomerations that consists of 10 factors and 22 indicators, and a Q-type cluster analysis is employed to quantitatively group five kinds of the urban agglomerations: mature export-oriented type, dual-core catch-up type, environment-friendly type, single nuclear radiation type, and inland extensive type. Finally, by synthesizing the classification results of different levels and quantitative clustering, China's urban agglomerations are divided into 10 subgenera: National mature export-oriented genre, national dual-core catch-up genre, regional dual-core catch-up genre, sub-regional environment-friendly genre, local environment-friendly genre, regional single nuclear radiation genre, local single nuclear radiation genre, regional inland extensive genre, subregional inland extensive genre, and local inland extensive genre.