The Southeast Asian countries are preparing to be integrated as one economic community and the accounting information will play an important role for trading and capital transferring, both within this region and between Southeast Asia and other regions. However, there are still obvious differences in the domestic accounting standards implemented in each country. This research focuses on the comparison and the effect of International Financial Reporting Standards on the quality of accounting information among 6 countries in ASEAN; Malaysia, Singapore, the Philippines, Indonesia, Thailand, and Vietnam before the integration of the ASEAN economic community (AEC). The accounting quality in this research is measured in terms of earnings smoothing, earnings management toward targets, and timely loss recognition. It is found that the difference in the level of earnings smoothing among countries increased after the declaration of AEC establishment which indicates less comparable. On the other hand, the overall level of earnings management toward targets decreased, which implies that the accounting quality ABSTRACT