Abstract: Coal mining activities damage native landforms and surface vegetation and destroy the environment of mining area and its surroundings,which lead to the reduction of vegetation-soil carbon sink,and a great loss of carbon reserves in the farmland ecosystem. In order to quantify the ecological impact range of coal mining on farmland and evaluate the carbon sequestration loss of farmland ecosystem,this paper took the Changhe basin mining area as an example and es- tablished a method for estimating the carbon sequestration loss of farmland eco-system caused by coal mining. In this paper,the directly damaged area and reference area of farmland were con-firmed based on mining area data,remote sensing data,climate data and geographical data,etc. Indirect damaged area was confirmed by calculating the variation trend of normalized vegetation index (NDVI) around directly damaged area. ESTARFM and CASA models were used to calculate the carbon sequestration of farmland vegetation and the farmland soil organic carbon was sampled and test- ed. The carbon sequestration loss of farmland ecosystem was calculated based on the change of land use in the mining area. The results showed that from 2000 to 2015,the direct damage area of farmland caused by coal mining in the Changhe basin mining area was 5. 06 km2 ,and the indirect damage area was 18. 99 km2 . The carbon sequestration of vegetation in the mining farmland was 3 936. 16 t / km2 ,and the soil carbon storage was 6 737. 05 t / km2 . The total car- bon sequestration loss of the farmland ecosystem in the mining area was 30 737. 68 t,among which the carbon seques- tration loss in the directly damaged area accounted for 42. 12% of the total loss,and the carbon sequestration loss in the indirectly damaged area accounted for 57. 88% of the total loss,indicating that the indirectly damaged area should be included in the ecological damage assessment. The influence of coal mining on carbon sequestration in farmland e- cosystem belongs to a carbon loss effect.