In the era of so-called knowledge-based economy, the creation and utilization of IT and new knowledge are recognized as core factors to enforce IT industry and to increase national competitiveness. Advanced countries, therefore, have heavily invested their resources on IT sector and introduced competition into the telecommunication market. ASEAN countries are trying to make themselves informationized society through IT market liberalization and industry development. They are investing lots of resources to construct IT infrastructure such as wired and wireless network and consider informationized society promotion as top national agenda. In this effort, Korea is a benchmarking model for them. Successful entering into ASEAN market requires close analysis and correct understanding of its IT policy and infrastructure. In this paper, therefore, tried to analyse IT policy and infrastructure of three ASEAN countries, which have high potential of economic cooperation in IT with Korea. And based on the analysis, tried to find out ways to enter into ASEAN.