Delimiting the ecological conservation redline is important to promote the coordinated development of Beijing-Tianjin-Hebei region, which plays an important role in the management and control integration of ecological space in the whole area. Five typical factors including water conservation, soil conservation, sand fixation, land desertification and soil erosion were selected to establish evaluation models of ecosystem service importance and eco-environmental sensitivity by using Remote Sensing (RS) and Geographic Information System (GIS) technology in the present study. A research was conducted on ecosystem service importance and eco-environmental sensitivity to reveal their spatial features in a quantitative way, and define the boundaries of ecological conservation redline using the data of the Second National Land Cover Census in Beijing-Tianjin-Hebei region. Results showed that the area of ecological conservation redline in Beijing-Tianjin-Hebei region was 66800km², accounting for 30.9% of the total area of Beijing-Tianjin-Hebei region. The ecological conservation redline were distributed in Yanshan Mountain, Taihangshan mountain and Bashang plateau of Hebei province. The main land use types were forestland and grassland with the areas of 77.9% of total protection area in ecological conservation redline, which is 55.7% higher than the outside of ecological conservation redline; and the annual average NPP in ecological conservation redline is also 23.5% higher than the outside of ecological conservation redline in Beijing-Tianjin-Hebei region. Therefore, the results are in conformity with the principle of "smaller areas get larger ecosystem services". The ecological conservation redline can be regarded as the most important areas that need to be strictly protected in Beijing-Tianjin-Hebei region.