The objective of this paper is to investigate the mechanism of labor force participation in Japanese farm households. For the purpose of empirical study, Tobit type 2 model is applied to the Farm Household Survey Data. The marked findings is that in the labor force participation decision of male members, the family system has an important role as well as the market wage and the farmsize, and the off-farm income of the female earner and the number of dependents are less significant.