Of the many ways of interaction between states, party diplomacy plays a unique role in shaping international relations. The Communist Party of China (CPC) has been distinctively characterized by its international background since the day of its founding and has always taken a strong initiative toward internationalization in the process of ensuing growth and rise. Its passion for external exchanges and communication has become an outward expression of its inbuilt international nature. The CPC shares a long history of interaction with its counterparts in Southeast Asia, which can be roughly divided into four stages: the hostile stage, the probing stage, the breakthrough stage, and the stage of deepening coordination. It fully shows the dynamics underlying inter-party relations and the clues for evolution in the regional landscape. A careful investigation into this history reveals that China's party diplomacy in the region is marked by the diverse format of exchanges, the adoption of inclusiveness, the constructiveness of cooperation agenda, and the progressiveness of outcomes. Looking into the future, China's party diplomacy in the region is ushering in new opportunities. Party-to-party interaction is becoming more desirable for both China and Southeast Asian countries. The agenda has been expanded to cover a broader scope and the interacting process between the two sides is now smoother than ever. Nonetheless, challenges still abound. China's party diplomatic efforts are susceptible to the volatility of domestic politics in Southeast Asian countries as well as emerging hotspot issues. The agenda and participants of party-to-party interaction often change fast. Consensus reached through party diplomacy is often hard to translate into actions. To achieve success in party diplomacy, parties involved should aim for policy goals that are common and universal, engage with each other as equals, collaborate to make forward-looking plans and catalyze constructive actions, thus laying a solid foundation of enduring peace and prosperity for the region and the world.
