Customs duties applied by the European Union on agricultural products differ greatly compared to WTO bound duties. This difference is essentially due to the importance of preferential regimes in the EU's trade agreements. It is estimated that nearly half of EU agricultural imports benefit from a preferential tariff (Gallezot, 2003). For this reason, an analysis of the tariffs applied by the EU cannot be limited to the multilateral framework of duties that respect the Most Favoured Nation clause but must be broadened to include all preferential systems. The objective of this project is to undertake a detailed assessment of European tariffs by relying on official regulations. The aim here is to realize a database which enables an easier analysis of all EU tariffs. The great difficulty of this operation being the simplification, without a loss of information, of a complex legislation which sometimes applies to very short periods of time (a few days only in the case of cereals) or, even more generally, which concerns specific duties (tax in monetary unit per unit of measurement of products). This is why, in order to meet the requirements for comparing and aggregating duties, a transformation of specific duties into advalorem equivalents will be undertaken. We will first present the sources mobilized for this study, then the principal considerations on European agricultural protection. To this end, the hypotheses adopted for this project will be discussed. Finally, a description of the resulting database and the methods for using it will be evoked.