Abstract: As an important drinking water source in Taizhou City, Changtan Reservoir is of great significance to regional development and social stability. Taking Changtan Reservoir as the research object, the delimitation and ecological restoration of the lake littoral zone and lake buffer zone were carried out in Changtan Reservoir under the guidance of Technical Guide for Delimitation and Ecological Restoration of Ecological Buffer Zone of Lakes and Reservoirs in Zhejiang Province (Trial). The results showed that the total length of the lake littoral zone of Changtan Reservoir was about 97 km. The lake littoral zone was divided into six types, including mountain type, natural beach type, farmland type, road type, estuary type and reservoir dam type, accounting for 42.6%, 25.3%, 3.4%, 20.6%, 7.6% and 0.5% of the total length, respectively. The lake buffer zone of Changtan Reservoir was divided into three types, including mountain type, farmland type and reservoir dam type. The area of these three types of buffer zones was 46.73, 2.89 and 0.168 km², respectively. Based on the delimitation of the lake littoral zone and lake buffer zone of Changtan Reservoir, the main environmental problems were identified and key ecological restoration areas were selected. From the aspects of disturbance removal, pollution prevention and ecological restoration, targeted ecological restoration countermeasures were proposed to create a reservoir ecological buffer system with strong capabilities of protection and adjustment, and harmonious coexistence between man and nature.