Utilizing the opportunity of economic reform and opening , northern countries quicken their steps to incorporate in the region and world economic development systems , actively approach the regional cooperation organization - - asean . moreover , their successively becom - ing members of asean makes it possile that the idea of the southeast asia community come ture . meanwhile , depending on their advantages , souther ncountries develop the trade and economic cooperation with northern countries , profitably expand more and more markets in northern countries 北方四国借经济改革开放之际加快了融于区域经济和世界经济发展体系的步伐，积极靠近东南亚区域合作组织东盟，先后加入了东盟组织，使东南亚共同体的设想成为可能；而南方也凭借自己的优势发展与东南亚北方国家的经贸合作，趋利避弊地向北方开拓更为广阔的发展市场，东南亚经济区域整合的进程加快了。
