This study examined patterns and determinants of families’supplementary educational investment on children. By supplementary educational investment, it meant the amounts of money spent on children’s education other than regular formal schooling expenses. The data used were from the 「1996 Household Expenditure Survey」conducted by the National Statistical Office. The statistical methods employed were descriptive statistics, cluster analysis and logistic multiple regression analysis. Results of cluster analysis revealed five different patterns of family supplementary education expense with relatively even proportion of families allocated to each pattern. The five education expenditure patterns were arts education dominant; other education dominant; gymnastics·clerical·computer education dominant; college entrance exam preparation dominant; and private tutoring dominant. Results of logistic regression analysis showed that the possibility of being in a pattern affected by various family socioeconomic variables. Important factors affecting there patterns were children’s schooling stage, residence, and mother’s education.