The aim of this thesis is to examine to what extent China acts as a superpower in the South China Sea. In order to accomplish the purpose of the study the International relations theory Offensive realism has been applied. The thesis is a case study, with the premiss to test Offensive realism on the selected case. Data is gathered from books and articles. Within the framework of Offensive realism, three categories have been selected to study China’s actions on three different occasions. The categories that have been applied are diplomacy, economy, and military. The occasions occur at different time periods, 1974, 2012, and 2014, in order to be able to give the study a wide basis.   The result shows, that from an Offensive realism perspective, China acts like a superpower in the South China Sea. In the cases studied China acts as a superpower in all of them. Breaking it down to the applied categories, diplomacy, economy, and military, it is showcased that China’s actions in the region are corresponding to that of a superpower eight of nine times. China seeks control of the region's wealth to strengthen its own economy, which in turn strengthens the country's military. Furthermore, the growth of the economy and resources means that control of the area is centered to China. Which increases the chance for China of creating a hegemony in the region.