Abstract: During the period from the Kyōhō famine to the last days of the Tokugawa shogunate, population growth stagnated in many areas of Japan due to disasters and epidemics, abortions and mabiki, and farmers quitting agriculture and leaving the countryside. To solve the economic and political difficulties caused by this, many domains carried out childcare reforms. During the KanseiBunka period and the Tenpō period, Mito Domain introduced childrearing relief, a population control system, and a ban against abortionmabiki. The discourse of population increase was also based on the population theory of agriculturalism, which developed with the reform. In the fight against abortionmabiki and in saving the loss of agricultural population, the Mito scholars theory was originally based on the idea of benevolent policy to impose ethical instructions on individuals and purge the administrative style, which was developed into a strategy to suppress leaving farmers from the agricultural political theory. Eventually, under the pressure of external threats, the theory is integrated into the context of nationalistic discussion. The population was regarded as an important resource to safeguard Japans interests, security, and superiority. This deduction is both a product of the changing diplomatic environment and the source of the modern wartime concept of fertility mobilization.

Key words: late Tokugawa Japan, population increase, Mito Domain, childcare policy, population thought