Following the emergence of China and its increasing influence in East Asia, the United States is reviving its attention and presence in the region, despite its long tradition of military presence in Japan and South Korea. This raises the question that with US pivot to the region how would be the pattern of security arrangements in the region? The present article applying the theory of ‘regional integration’ would assess the role of ASEAN and its regional forum in shaping and managing US-China rivalry in the region. It concludes that, based on a multi-polar system approach, a regional-cooperation-based security pattern, and applying preventive diplomacy, AEAN has been active in security arrangements of the region and successfully prevented tension and conflict between China and the United States in this region.