Résumé : This thesis discusses how ideas, as domestic factors, have decided the formation of China’smultilateralist foreign policy. It tries to provide an profound understanding of China's foreignpolicy development with the theoretical tools provided by discursive institutionalism andhistorical institutionalism.Three empirical cases are studied: the case of WTO, the case of ASEAN+3 and the case ofShanghai Cooperation Organization (SCO). These three cases have represented China'sinvolvement of multilateral institutions at different time and level.The findings show that China has gradually turned to an active participants of multilateralinstitutions, and it is trying to constructing a new type of multilateralism: competitivemultilateralism. Whether it can be compatible with existing institutions is an open question.