Abstract: "Thailand has recently strengthened its economic policy toward its neighboring countries in coordination with domestic regional development. It is widely recognized that economic cooperation with neighboring countries is essential in preventing the inflow of illegal labor and effectively utilizing labor and resources through the relocation of production bases. This direction is strengthened by elaborating the GMS-EC and the ECS (Economic Cooperation Strategy). In addition, economic dependency of the neighboring countries on Thailand is generally high. In this report, firstly, Thai regional development policy will be made clear in relation to its economic policy toward neighboring countries as well as the status quo of the industrial estates. Secondly, Thai policy toward the neighboring countries is examined referring to the concept of wide-ranging economic zones, regional economic cooperation and special border economic zones. Thirdly, the paper will discuss how closely the economies between Thailand and the neighboring countries are related through trade and investment. Lastly, some implications on Japan?s economic cooperation will also be explored."...Keywords: industrial estates, GMS-EC, ECS, economic corridors, border zones