This article presents the results of changes in urban construction land and driving forces of urban agglomerations in China. First, the urban construction land areas and the urban construction land areas per ten thousand persons were compared in the Jing-Jin-Ji urban agglomeration, the Yangtze River Delta urban agglomeration, and the Pearl River Delta urban agglomeration from 2000 to 2008. Second, a dynamic degree model was used to express changes in urban construction land areas at different periods and to present the spatial traits of the changes using geography information system software (9.0). Furthermore, cointegrated relationship analysis and the Granger causality test were adopted to analyze the correlation between urban construction land area and the influential factors. The conclusions are that (1)the periodicity of urban construction land area increase in the three urban agglomerations is obvious, and the rate of increase before 2005 was higher than after 2005 for all three urban agglomerations; (2)the difference in dynamic degree was significant among the different periods, and the dynamic degrees were the largest at the beginning of the total period. There was an obvious difference in the urban distribution of higher dynamic degree in each urban agglomeration; (3)all three urban agglomerations displayed highly significant correlations between the urban construction land area and the influential factors, and there were significant differences in the factor distribution and influential direction of Granger causality at the certain probability; and (4)the relationship of the Granger causality at a lag of 2 was more obvious than at a lag of 1.