The UN Security Council (UNSC) has been under an increasing international spotlight with the wars in Syria and Ukraine and the vetoes of some of its five permanent members (P5) in these wars. Yet, the P5 behave differently in and towards the UNSC, and this difference is not (only) explainable by material factors but also, as constructivist IR theory would argue, by the different ideational perspectives they have about world politics and their place in it. This paper deals with China’s conduct in and toward the UN Security Council from a constructivist perspective. China’s behavior rests on several notions, such as non-interference in the internal affairs of a State, and respect for its territorial integrity, as well as opposition to the use of force for regime change. China perceives the world as multipolar and pluralistic and considers that world politics should be conducted in a prudent and constructive manner that is based on consensus through consultation (among great powers) and the respect of the interests of all parties (including small and middle States). Since the start of the 21 st century, China has been increasingly more active and assertive in the UNSC, which is evidenced by the fact that it is the permanent member with the most abstentions during this period and the only permanent member that has used the veto more times after the end of the Cold War than during it. At the same time, China wants to portray itself as a “responsible great power” in the UN and in the global order and pays considerable effort in building and maintaining this image. Yet, it stands for a restrictive interpretation of key concepts for international peace and security, such as sovereignty, responsibility, and threat to peace, and is not keen on Security Council reform.