The focus of this article is on the concept of activation, which has been discussed in OECD and EU member states since 1990s. There are five sections including: firstly, the definition and the historical background of this term, as well as the comparison with other related concepts will be presented. Secondly, the typology of activation will be analyzed. The third section is to illustrate the role of social assistance towards activation. Since social assistance has become a significant area for implementing activation, it needs to be taken into account. The fourth section discusses the effectiveness and impacts of the related programs. Finally, policy implications and suggestions will also be presented.