Abstract: With the acceleration of regional collaborative integration, the shortage of soil and water resources along with the degradation of ecological environment have brought great pressure to the high-quality development of cities. Constructing the regional ecological security pattern is regarded as a effective way to alleviate the contradiction between ecosystem protection and social development. Choosing Southern Jiangsu urban agglomeration as the studying subject, the paper identifies ecological supply source by the combination of MSPA method and landscape connectivity assessment. Besides, the ecological demand source is selected by the ecological scarcity evaluation. Further, extracting the ecological corridors coupling supply and demand space by applying the minimum cumulative resistance model. Finally, setting the strategic points and landscape ecological security pattern was then constructed．The results show that (1)The total area of the ecological supply source is 4 876.76 km², accounting for 17.36% of the study area. The total area of ecological demand sources is 2 099.8 km², accounting for 7.48% of the study area.(2)55 ecological supply corridors and 199 ecological supply-demand corridors are constructed, with a total length of 2 296.95 km.(3) 98 strategic points were obtained as the key spatial nodes of urban ecological construction in the future. The research can offer references for the Yangtze River Delta region, which includs the Southern Jiangsu urban agglomeration, to optimize the territorial space development pattern under the guarantee of ecological security. Also, the research provides a reference for the construction of ecological security pattern of other high-density urban agglomerations in China.