Abstract: By using the evaluation approach of ecosystem services (including mark et value, opportunity cost, restoration cost, and shadow project approaches), an d combining with situation investigation, the ecosystem service loss in Mentougou District of Beijing City caused by coal resource exploitation in 1949〖KG-*2〗- 〖KG-*7〗2006 was systematically evaluated. In the study area, coal mining mainl y induced the cost increase of solid waste disposal and sink reclamation, and th e losses in food production, water self-preserving, residents moving, and water and soil resources. The ecosystem service loss caused by the coal mining in 194 9〖KG-*2〗-〖KG-*7〗2006 was about 543 billion Yuan RMB, approximately 9 times high of its market economic benefit (59 billion Yuan RMB). It was very diffic ult or needed a long time to restore the damaged ecosystem.

Key words: nitrate, source identification, stable isotope technique, pre-treatment method.