After the enforcement of Waste Management Law in Korea from 1987, a systematic waste management has been made. Since then major effective policies and strategies by the government were utilized to promote reduction and recycling of waste and to implement appropriate technologies for disposing waste in safe and permanent methods. In recent the waste becomes not a waste being disposed of but resources having values, so management policy is focusing on ‘waste to energy’ as one of renewable energy resources and the establishment of ‘sustainable and recirculating society’. By such practices for last 30 years in South Korea, the recycling rate has increased from under 10 % to 80 %, and the share of landfilling became less than 10 % in overall waste streams. Using the WARM code developed by US EPA, the greenhouse gas emissions by different practices of waste treatment were estimated for 30 years. Due to a significant increase of recycling rate, the reduction of greenhouse gas emission was achieved around 110,000 tons of CO2, from around 25,500 tons of generation to 85,000 tons of credit. The paper will present such changes in different waste streams by effective waste management efforts for last 30 years.