The great achievement of Kondo Yasuo in a double-entry book-keeping system for family farms has been noted in the history of farm accounting in Japan. In this paper we tried to organize his accounting theory from the point of view of accounting theory history. The characteristics of his concept of bookkeeping for farm households were clarified and the contemporary significance and the challenges of his accounting theory were raised. The findings show that Kondo Yasuo's accounting theory has two realistic significances. The first is that it adopts double-entry bookkeeping. Second, it applied to both management expenses and household expenses.