Southeast Asia is one of the regions in the world that are most vulnerable to climate change. Climate hazards, such as temperature increase, erratic rainfall patterns, and extreme climatic events, disrupt ecosystems, livelihoods, and various aspects of human systems. Climate change threatens agricultural production, consequently endangering food security, ecological stability, and sustainable development.The research composed of national studies from the participating member states focused on climate change adaptation measures employed in crop production systems of rice, maize and cassava following the Value ChainApproach. The research composed of national studies from the participating member states focused on climate change adaptation measures employed in crop production systems of rice, maize and cassava following the Value Chain Approach. It has the following objectives-1To identify good practices in the ASEAN region, which address climate change related vulnerabilities that could lead to food insecurity of the three critical food crops in the regionRice, Maize and Cassava using a value chain mapping approach.-2To identify where vulnerabilities exist or are likely to exist, in the supply of the identified food crops, with a primary focus on production and related inputs and a secondary focus on post-production activities; specifically drawing out where regional collaboration could be most valuable.-3To identify the good practices in terms of its technical requirements for practical applications, institutional issues and implementation challenges focused on scaling up regionally. -4To use the learning from existing good practices to stimulate and spread meaningful action across the region.