East Asian integration faces challenges regarding development, including income gaps, human development, and poverty eradication. There are movements to bolster efforts to achieve regional integration in Southeast Asia, with the goal of integrating the entire ASEAN community by 2015. There are also challenges most notably on the reduction in the development gap between Cambodia, Lao PDR, Myanmar, and Vietnam (CLMV countries) and others in the ASEAN. An effective utilization of limited developmental finances requires a systematic and comprehensive approach to development cooperation in the region in order to raise the aid effectiveness. Accordingly, this study undertook a quantitative analysis of the developmental needs of East Asia, identifying areas with higher levels of need for development, and suggests measures for implementing programs for cooperation. This study is significant because it was able to identify the main areas for development cooperation by quantitatively analyzing the economic circumstances and development gaps in East Asia. It also revealed the inability of quantitative analysis to reflect the characteristics of each country and provide a detailed description of the developmental capacity of recipient countries in the region. The challenge for the future will include building a more systematic analytical model by factoring in analyses of donors` comparative advantages, which can contribute to the reduction in development gaps with respect to recipient countries in Southeast Asia.