Calculating the value of ecosystem services may improve economic efficiency and play an important role in protecting ecosystems.The grassland ecosystem of HulunBuir city is an important component of ecology security system in Northeast China and is the typical belt transect of International Geosphere Biosphere Programme global change study. In this study, net primary productivity (NPP), as an improtant ecological parameter, was used to estmate the services value. Considering the characteristic of satellite imagery, it is difficult to calculate some functions. So we calculated the services value from four aspects, including soil erosion control, water conservation, direct production and gas regulation. The total services value of grassland ecosystem was estimated in RMB to be aproximately 18.47×109Yuan in 2006 (Chinese currency, 7.78 Yuan=US$1), the average economic value of unit area was 15.4×104Yuan/km2. The direct production value was 1.23×109Yuan/year; and the contribution rate to total value was 6.66%. Indirect services value was 17.24×109Yuan/year, and the contribution rate to total value was 93.34%. Indirect services value was far more than direct production value. For the indirect services value, the water regulation value was the maximum, 9.09×109Yuan/year. Gas regulation value was 5.25×109Yuan/year, contributing 28.42% to the total value.