We look into the responses and changes in Southeast Asian economy after the global economic crisis in 2008, focusing on three big Southeast Asian countries; Thailand, Malaysia, and Indonesia. We include the comparative study between Asian economic crisis in 1997~98 and global economic crisis. We also suggest some policy implications for overcoming the economic crisis. After the global economic crisis all the three countries, in common, have experienced instability in financial market and economic depression such as contraction of consumption and investment, and decrease in export. To overcome the economic downturn, the governments have been implementing expansionary fiscal and monetary policy. Nowadays stock indexes, exchange rates and macroeconomic indicators have been recovered to the pre-economic crisis level. This may reflect that Southeast Asian economy have the bigger capability to overcome the economic crisis. This may be partly due to economic reform such as the restructuring of business and banking sector, and the establishment of law and institution for exchange and capital markets. Also, it may be partly due to the accumulation of international reserves as the buffer against potential economic crisis. For policy implications, we could suggest continuous economic restructuring, cooperation on macroeconomic and exchange policy among ASEAN countries, and ASEAN+3. Briefly, the negative effect of global economic crisis on Southeast Asian economy seems to be smaller than that of Asian economic crisis. However, it is obvious that the stronger competitiveness and cooperation are inevitable to overcome the potential economic crisis in the future.