This paper discusses the optimal environmental and tariff policies in the case where a country must choose among various alternatives designed to mitigate pollution level abroad. A greater tariff on foreign import will reduce the pollution level by decreasing the output. The optimal tariff ought to be lower on the import from advanced economy where anti-pollution policy is more rigorously enforced. Because the production activity often occurs in foreign countries where direct monitoring and control on pollution is necessary to lessen the production externalities. In this setting, a pollution tax imposed by foreign government is shown to be optimal in absence of coordination between two governments. In the presence of coordination, the optimal policy is indeterminate, i.e., it can be a tax or subsidy.