Abstract: The construction of regional land ecological network is an important content of land ecological construction. In the current research, the selection of multi-scale ecological source sites involves less research, and further research is needed. This paper takes Jiangsu Province as the research area and conducts evaluation of land ecological sensitivity and importance based on land use survey data. On this basis, sensitive, extremely sensitive, important, and extremely important vectors were selected and ecological source places were determined through threshold screening. Ecological corridors were then generated to form a multi-level land ecological network system plan in Jiangsu Province. Results of the research are: (1) The land ecological network system of Jiangsu province consisted of 31 primary sources, 175 secondary ones, 1313 third-level ones as well as 61 primary corridors, 345 secondary ones, 3882 third-level ones, and the area of those was 23 526.26 km2, accounting for 22.04% of the total area of Jiangsu. (2) The primary ecological sources were mainly composed of river, lake and wetland area, while the majority of the second and third ones were paddy field and woodland. Among these, the Yangtze River, Taihu, Nantong section of coastal wetlands, Hongze lake, Gaoyou lake, the southern section of Yancheng coastal wetlands, the northern section of Yancheng coastal wetlands, Luoma Lake, Ge Lake, Baima Lake were the most fundamental ecological sources, with the integral index of connectivity (dIIC) standing in the top 10 list among 1 519 ones, which made great contributions to the land ecological connectivity in general. (3) The results of evaluation of land ecological sensitivity and importance are key foundation and basis of the selection of ecological sources. In addition, a combination of ecological sources and corridors can better realize the planning of regional land ecological network.