The European Union market is the most attractive market in the world. This is confirmed by the fact that here are millions of consumers on the market who create demand for quality goods and services, it is a unique market where transparent rules and regulation supply, it has a secure investment framework and is the market most open to developing countries and those least developed countries in the world. Joining the European Union's unique market, which involves the free movement of people, goods and services, is in itself a major change that opens up many opportunities and creates new opportunities, but also presents challenges and threats. Doing business in a large market is an advantage for those who know how to take advantage of opportunities, but on the other hand, it also has pressure because of significantly greater competition. Although certain changes occurred with Croatia's accession to the European Union, our economy was integrated into the European Union even before membership. By signing the Stabilization and Association Agreement, trade has been largely liberalized. How important the European market is to us is the fact that most foreign investment comes from EU member states and most of Croatian imports and exports are related to the EU market. Another change in joining the European Union is evident in financial terms.Also, by joining the European Union, Croatia has funds from European funds that are far higher than it was available when it was a candidate for EU accession. The aim of this paper is to clarify the trade policy pursued by the European Union, as well as the instruments for the goals of these policies, as well as the policy bodies and their policies pursued. The purpose of all this is to provide a detailed analysis of the European Union's single market.