In recent years, land urbanization, as a spatial manifestation of China's expanding urbanization, has emerged as a core research field within urban geography and land science. Provincial administrative departments within China's distinctive administrative system significantly influence municipal administrative departments and urbanization levels. Individual-level influencing factors cannot fully explain the Chinese mode of urbanization. Therefore, a multilevel linear model was developed to identify factors influencing China's land urbanization process. The results indicated that in 2005, factor inputs, in particular, and public service critically influenced land urbanization in municipal urban areas. By 2016, economic development levels had superseded factor inputs, public service, and population agglomeration as the key influencing factor. At the provincial level, differences in economic development levels critically influenced land urbanization. The provincial government's prioritization of ecological and agricultural resource conservation had a significant negative impact on city-level factors and urban built-up areas. The relationship between the government's developmental attitude, geographical locations, and city-level factors was complex and varied according to regional development levels. A further finding was that since China's reform and opening-up policy was initiated in 1978, land urbanization has been driven by industrialization and urbanization, gradually shifting from government-led to economy-driven stage. Thus, a multilevel study of land urbanization reveals mechanisms and cross-level relationships among different factors that influence levels of land urbanization. Moreover, it provides a theoretical basis for rational policy formulation.