This paper challenges both rationalist and constructivist approaches in explaining China’s foreign policy behavior toward multilateral institutions after the Cold War. Borrowing insights from socialization theory and operational code analysis, this paper suggests a ‘superficial socialization’ argument to explain China’s pro-multilateralist diplomacy after the Cold War. Using operational code analysis to examine belief changes across three generations of Chinese leadership and on different occasions, we argue that China’s pro-multilateralist behavior is a product of ‘superficial socialization’, in which Chinese foreign policy elites change their beliefs about the outside world and regarding the future realization of their political goals in multilateral institutions. However, Chinese policy makers have not changed their instrumental beliefs regarding strategies even in multilateral institutions. China is indeed socialized through multilateral institutions, but its scope is still far from the ‘fundamental socialization’ stage when states’ interests, preferences, and even identities change.