Abstract: In order to evaluate the ecological environment of the Yarkant River plain oasis in the past 25 years and the level of coordination between it and the economic development, land use data were interpreted from remote sensing images on 1991, 2005 and 2016. Referring to the China terrestrial ecosystem service value scale and combining with the biomass status and the willingness to pay of the study area, the ecosystem service value per unit area was revised. Then the ecosystem service value was calculated by the equivalent factor method. The suitability of VC in this region was tested by sensitivity analysis, and the degree of coordination between ecological and economic development was quantitatively evaluated with the help of the eco-economic harmonious index (EEH), so as to lay a foundation for the reconstruction of ecological security pattern in the study area.The results showed that:(1) Except the cultivated land and the construction land, the area of other land types decreased, and the forest land area decreased by 47.12% in 1991-2016. (2) During the study period, the ecosystem services value decreased by 22.08×10⁸ RMB, with an average annual decrease rate of 0.20%, which was mainly caused by the decrease of forest land, water, unused land and meadow area. (3) The service function of the study area was far greater than the productive function, in which the value contribution rate of the regulation service was 78.05%, and the value contribution rate of the cultural service was 3.22%. (4) Sensitivity analysis showed that ecosystem services value was not elastic to the value coefficient introduced, which indicated that revised value coefficient was suitable for the region. (5) The analysis of eco-economic harmonious development showed that the study area in the low conflict space during 1991-2016, in addition to Yecheng, Bachu county, was low harmony, and the rest of the county was low conflict and conflict degree of Shache County was more obvious. The study shows that the regional ecological environment has deteriorated in the past 25 years, and the ecological and economic development has changed from low coordination to low conflict. In the future, ecological protection should be strengthened to promote the transition from conflict zone to coordination zone.