The purpose of the study is, based on implementation theory and Lennart Lundquist’s three concepts- understanding, capability, and willingness, to identify whether these factors can affect the implementation of the Paris Agreement in four countries. Through a qualitative text analysis of the NDCs (Nationally Determined Contributions) of four countries, using understanding, capability, and willingness as categories, various aspects have been identified and are presented in the results. The study focuses on four countries with similar climate and economies to establish criteria as closely as possible. The study takes a hermeneutic approach as the authors interpret the material. The results indicate that the countries understand the Paris agreement and why implementation is necessary, considering the environmental issues present today. The countries also present measures for implementations, such as economic or technical aspects on how to achieve the goals of the Paris Agreement, as well as their priorities in relation to their circumstances. The countries also demonstrate a willingness to carry out implementation, and their ambitions are considered high based on their explanations. The conclusions highlight that implementation theory, and the three concepts of understanding, capability, and willingness can be used to understand the context in which countries implement the Paris Agreement.