The purpose of this study is to analyze the inequality of the farm household income and to decompose its factors with the panel data of Farm Household Economy Survey in 1998∼ 2002. The inequality trend of farm household income is assessed by inequality index decompositions by income source, by farm manager's age and by the standard farm size. The main results in this study are followings. Frist, the inequality of farm household income among farms is being aggravated. Second, the result of farm income source inequality analysis shows that the inequality of farm income holds the largest portion in the inequality of farm household income and the portion is being increased. Third, the inequality among farm manager's age is aggravated. Especially, the inequality of farm household income and farm income of under 30-year-old are making worse. Fourth, the smaller the standard farm acreage, the worse the inequality of farm household income and farm income.