This paper examines the implications of unequal income distribution among individuals on optimum tariff. It derives new optimum tariff formulas and shows that the distributional characteristics of individuals' shares of imports and revenue distribution are crucial in determining the optimum tariff rate. It also shows that unequal income distribution has different implications for trade policy; for example, a small country's optimal policy in general is not free trade. The paper also examines the implications of a number of social welfare functions on trade policy and discusses the symmetry between export and import taxes.