Abstract: With the rapid development of marine ranching in China, the location of marine ranching is critical to its construction and development. This paper takes Yantai as an example, which is the demonstration city of marine ranching construction in China. Based on marine functional zoning and other social factors, six proposed areas of marine ranching A to F are selected in the northern sea area of Yantai. Then, the indicators of water depth, hydrodynamics, sediment type, water quality and sediment quality, chlorophyll a, eutrophication status and other indicators were selected to evaluate the suitability of marine ranching sites in each proposed area. By calculating the comprehensive suitability index of marine physicochemical environment for each proposed area, it is found that: the comprehensive suitability index in area A is the highest and that in area C is the lowest. For the suitability of marine ranching construction in the entire proposed area, 36.88 km² area is the most suitable, 625.63 km² area is suitable, and 318.88 km² area is not suitable. In terms of marine biological environment, the difference of chlorophyll a in the proposed sea areas was small, but the content of chlorophyll a was low in summer; area F is prone to seawater eutrophication pollution in summer and autumn, which is harmful to the healthy operation of marine ranching. This study provides support for the site selection and construction of marine ranching in Yantai northern sea area, and also provides a reference for the construction of marine ranching in other regions.