The paper argues that from 1899 to 1903, Liang Qichao developed his own theory of the state. This theory mainly includes four parts: First, the theory of the transitional era emphasizing "out with the old, in with the new" is now the foundation for the radical reform. Second, the constitutional monarchy with the separation of the executive, legislative and judicial powers is the goal of the form of the government. Third, the combination of the state sovereignty and popular sovereignty has been used as a new sovereignty theory for defending national independence. Fourth, the road of the "New Citizen" has been chosen as the chief method for saving the country from perils and seeking the progress for the nation. The contributions of Liang Qi chao on the theory of the state laid the foundation for his historical status as a thinker of the enlightenment in the intellectual history of modern China.