In the world under changing economic structure in industrial, agriculture and service sectors, many countries tried to acclimatize and make their own national policy strategies, especially trade policy as a public policy that is considered important to society and the nation. The government must issue policies and implement them to improve their country’s economic progress and improve the living of people to the people’s needs and also stakeholders. Therefore, if they viewed that a government policy is useful, people will support their government more. It demonstrates relationships between people and the government. Especially, the 21st century is a century when the center of the world will move from the west to the east, i.e. Asia so that in the development of national economic policy, it is necessary to understand the trends and changes that are about to occur to be able to determine the direction and strategy of policy development in accordance with changes. This paper presents the definitions, significance and characteristics of public policy on international trade in Southeast Asia, as well as concepts and theories on public policy on international trade, actors in policymaking, and public policy on international trade in Southeast Asia, the impact of public policy on international trade, trends and directions of public policy on international trade. Opportunities and risks of Thailand is also presented to study the overview and relationships between Thailand and other countries in terms of public policy on international trade as a developing country that is a part of the global production network to acclimatize and prepare to improve, by using the methodology of document analysis. Therefore, this paper would help to study public policy on international trade, to understand the relationships in policymaking implementation and to support and develop trade cooperation in various aspects in this region.