The report focuses on the impacts and socio-economic and environmental changes brought about by the reforestation program on the Karen and Lisu ethnic groups at Pang Khum Village, Tambon Yang Moen, Samoeng District, Chiang Mai Province. It is found that the operations of the program have reduced forest areas. The two ethnic groups have had conflicts over water resources and arable land. However, in reality, their relationship is the unity of opposites. Lisu provide jobs to poor Karen due to labor demand. Therefore, the Karen do not want to relocate themselves to the lowlands. The state wants the two ethnic groups to remain in the area and the program should have strong impacts on them regardless of age or gender. The groups have to work harder in both domestic and non-domestic domains.