In this paper, a collective modeling framework is applied to analyze rural farm households’ labor supply behaviors in south China. The intrahousehold time allocation decision for on farm operation is influenced by household members’ off-farm migration behaviors, while the imperfect wage labor market in the rural areas imposes constraints on the off-farm labor supply and requires proper measure of farm shadow wage and shadow income. By considering the heterogeneity that exists among individuals, the value of labor time is associated with the production activities. The results reveal the disparity between husband and wife’s “wage” earning related to the distribution of nonlabor income. The interactions of income sharing contribute to the intrahousehold inequalities, which are essential to welfare policy analysis.