This paper quantifies the material wealth of prehistoric burials to systematically analyze burial wealth inequality over time in the middle Yangtze River plain. It explores the relationship between wealth inequality and multiple variables, including population, powers, hydraulic engineering works, and social stratification. The study addresses the nature of wealth inequality in prehistoric societies of this region and empirically tests and critically evaluates the “hydraulic civilization” hypothesis. Additionally, it compares data from the middle and lower reaches of the Yangtze River Plain, integrating historical records to propose a new model for state formation. This model posits that the centralization of political-military and ritual power by elites played a crucial role in the origins of the state.