Flood disasters this year (2554) affect the country in Southeast Asia to 6 countries. And also the most serious in the round 50 years in, however, this crisis is to demonstrate the cooperation and mutual assistance of the ASEAN member countries. As can be seen from the fact that the ASEAN members send help to each other. Both countries are as victims. But it also sent assistance to other countries such as Laos and Myanmar, with the level of economic development and later in a situation is to provide assistance to the victims. ASEAN also plays a role in the mitigation by sending the evaluation team moving เร็วฉุกเฉิน ASEAN (ASEAN-Emergency Rapid. Assessment Team-ERAT) at ground level. To assess the hazard of flood in Thai; the 15 October 2011 which consists of the members 5 people. From Brunei, Indonesia, Malaysia and Singapore work with the Thai side 3 people. Along with gave rice through enterprise emergency rice reserve of ASEAN plus three (ASEAN Plus Three Emergency Rice Reserve-APTERR) however, If no cooperate to solve the problem of flooding to cover more. The flooding problem will become the obstacles to the development of ASEAN members, especially in Cambodia, Laos, Myanmar and Vietnam, and will become an obstacle to build an ASEAN community.