The study focuses on the development of policy and implementation of Thai governments concerning Mon refugees and related ethnic groups from 1952 to 1995. Nineteen fifty-two was the start of refugee influx into Thailand from Burma. The expansion of communism in Southeast Asia was a major reason for the governments to be aware of refugees. Minority and Mon refugees were used as a buffer to prevent the expansion of communism in the west of the country. The 1976 Announcement by the Interior Ministry forbidding illegal Burmese refugees was the start of the laws differentiating displaced persons of Burmese nationality from illegal immigrants. After the bloody revolution in Rangoon in 1988, there were many groups of refugees coming into Thailand. There were many strict policies and practical guidelines forbidding the migration of minority ethnic groups, because the Burmese government was suspicious of Thailand being secretly supportive of minority groups. After the end of the Cold War, Thai policies on refugees have changed to take account of the economic benefits. Migration of ethnic groups has been strictly controlled, except for the purpose of foreign labor. The policy toward the Mon has been changed from providing political refuge to expelling from the country.