First Chapter INTEGRATION - The integration - An integration theory - The juridical boundary of the integration - An integration thinking Second Chapter EUROPEAN UNION, SOUTHERN COMMON MARKET AND LEGISLATIVE HARMONIZATION - European Union, Southern Common Market and Legislative Harmonization - Comparative Law - The Integration as process - Mercosul and European Union - Legislative Harmonization in the context of the Regional Integration Third Chapter MERCOSUL, EUROPEAN UNION AND TAX LEGISLATIVE HARMONIZATION – A STUDY ABOUT THE VALUE ADDED TAX - Tax Legislative Harmonization - Tax Legislative Harmonization in Mercosul