Prior to 1975.Thailand’s environment deteriorated due to natural resource usage and pollution especially in Mae Klong River which greatly impacted Thailand’s economic system. The government issued the act of legislation in promoting and protecting environment quality in 1975 and established the national committee, the National Environment Board, which has the deputy prime minister as its chairman. The office served as the secretariat office to conserve and assign environmental policy. In the first phase, the National Environment Board was under the office of the cabinet.

The two amendments of the act of legislation in 1978 and 1979 had assigned the Office of National Environment Board to be under the Ministry of Science and Technology

The government revised the environmental laws into act of legislation in promotion and protection of national environmental quality, 1992, to expand the environmental responsibility to cover local, national, and international cooperation. The act initiated 3 new departments: Office of Environmental Policy and Planning (OEPP), Pollution Control Department (PCD), and Department of Environmental Quality Promotion (DEQP); which replaced the Office of National Environment Board to push the policy and measure forward for more concrete results as well as responding to the government’s policy on decentralization management and environmental budget to the local area. The Ministry of Science and Technology has been renamed to the Ministry of Science, Technology, and Environment.

The Government administrative system reform has led to the enactment of the act of legislation in allocating ministries and departments in 2002. As a result, the Ministry of Natural Resources and Environment (MNRE) was found. The Ministry of Science, Technology, and Environment was transferred into the Office of Natural Resources and Environmental Policy and Planning (ONEP) on 8th October, 2002.