This article treats the complexity of the public policies in the social protection. Knowing the fact that this process is facing a lot of difficulties, they should be known and avoided by the public actors, involved in social security. At the same time, the implementation of policies consists of the choice of instruments used by the government to realize public policies. The choice of public policy instruments is linked to a diversity of factors and criteria analysed in this article. The purpose of article is to underline the complexity of the implementation of public policies and the choice of public policy instruments. In this article, we tried to bring examples of implementation of public policies in the situation of the European Union.