[Objective] To delineate the ecological protection redline in Chongqing Municipality under protection of ecological function in order to maintain the ecological stability and sustainable development.[Methods] Based on the characteristics of the regional ecological environment, the important factors of ecosystem service function such as water conservation, biodiversity maintenance and soil conservation, as well as the sensitive factors of soil erosion and kast rocky desertification, were selected to assess the ecosystem service function and eco-environment sensitivity in Chongqing Municipality.[Results] Four types of ecological protection redline areas with a total area of 30 790.91 km² were delineated, accounting for 37.33% of the total area of Chongqing Municipality. Ecological protection red line areas were mainly located in the Qinba Mountain, Wuling Mountain, Three Gorge Reservoir, Metropolitan "Four Mountains" and Dalou Mountains in Southern Chongqing Municipality.[Conclusion] In recent years, great progress has been made in the construction of ecological protection area in Chongqing Municipality, which plays a positive role in maintaining and improving the service function of regional ecological system.