Abstract: In the late 18th century，after Japanese scholars of Rangaku and political economists learned about the negotiation activities between Japan and Russia，they took this as a start and developed a wholly new set of political economy（Keiseiron）theory with modern national awareness，such as frontier region exploration，foreign trade and coast defense reorganization. Toshiaki was not only one of the outstanding persons but also the first political economist who promoted a whole set of economic theory in the late stage of Tokugawa. His theory covered politics，economy，military affairs，society，mathematics and many other subjects. Based on the analysis of the relationship between the Russo Japanese negotiations during Russia went southward in the late 18th century and foreign ideological transition of Japanese intellectuals as well as the formation and development of Toshiaki’s ideology，this article tries to further discuss the fundamental reason of Japanese intellectuals’ foreign ideological transition. Then we can have a profound understanding about the development of Japanese modern ideology in the late stage of Tokugawa.

Key words: Honda Toshiaki, Russia’s marching southward, foreign ideology, transition