The main purpose of this study is to see the impact of the export -import tariff reduction of the Indonesian manufacture commodities after the implementation of Common Effective Preferencial Tariff (CEPT) and its stimation on the value of export and import in 2003 and 2008. The model that was utilized was based on the formula developed by Ballasa and Kreinin (1967). THe result indicated that tariff reduction will create trade creation, an increase in the values of ezxport and at the same time the decrease of value in import.