Abstract: To improve and optimize pattern and functions of urban ecosystem, this study tried to indicate urban ecological security pattern conceptually based on correlative studies and chose Changzhou city for a case study. Urban ecological security pattern bythe least-cost distance model was established to integrate natural environment factors and landscape pattern characteristics. Because urban area was composed of social, economic and natural systems, this study divided urban landscape into four color classes according to the various landscape pattern and functions. Hereinto, red landscape was building area that supported living, production, and other social economic activities, gray landscape included different traffic lines and communication corridors could maintain diffusion and transfer of energy, money, products andinformation. Greenlandscape was composed of forest, cropland, and grassland and blue landscape contained river and lake both could preserve biodiversity and adjust environment. Through tracing the landscape function flows, positioning the interaction points of landscape functions, and identifying the frangible area with unsuitable land use, spatial extent with potential ecological risk could be deter mined. Finally, for urban growth and sustainable development, this study put forward urban ecological security pattern to relieve and save ecological risks by setting areas and rules of different land use zones such as prohibited zone, limited area, regulated area, optimized area and potential development area.

Key words: urban ecological security, landscape pattern, landscape function, least-cost distance model, Changzhou

摘要： 基于景观功能网络评价，提出城市复合空间优化方案，并选择常州市为研究区，实证城市生态安全格局理念在空间优化过程中的操作性。由于城市为整合社会、经济与生态功能的复合生态系统，本研究首先依据城市景观功能与结构特征，将城市空间结构分为支持社会经济功能的红色景观，维持能源、资金、产品与信息传播、流通的灰色景观、保持生物多样性与调节区域环境的蓝色景观及绿色景观。其次由功能网络连通性及其相互作用的角度分析城市景观格局、功能流路径与不同功能流在空间上的相互作用，以获得生态功能冲突与环境敏感区域的空间位置。最后，从功能整体协调发展角度，将研究区分为优化开发、调整开发、限制开发及禁止开等分区，针对其存在的生态安全问题，提出符合城市生态安全的空间优化方案。

关键词: 城市生态安全, 景观格局, 景观功能网络, 最小耗费距离模型, 常州