An optimized urban ecological network space pattern boasts of great significance for the sustainable development of urban ecological environment. The present work selected the center of Harbin city as the research area and adopted the "patch-corridor-matrix" theory to identify the ecological source, ecological corridor, ecological node, and ecological matrix in the research area and analyze the spatial distribution as well as the strength and weakness of the ecological network connectivity. Additionally, the GIS technique and CA-Marcov model were applied to a simulation and optimization of the ecological network pattern. The research results indicated that (1) the ecological source in the research area, compared with an external counterpart, maintained a closer contact with the outside world; only a small number of ecological sources or ecological nodes in the surrounding area were connected with the ecological corridors. The connectivity of ecological corridors mid-north and southwest of the study area was poor, that in the east remained at a medium level, and connectivity of ecological corridors. in the middle was good. The distribution of transferred-in large ecological land in the study area was concentrated while the distribution of transferred-in small ecological land in the counterpart was sporadic. (2) An optimized ecological source displayed a trend of concentrated distribution in the west-east direction and the north-south direction, and the connectivity between large ecological sources was relatively high. In the research area, large ecological corridors that formed between large ecological sources and between large and small ecological sources constituted the major ecological corridor network, while small ecological corridors that formed between small ecological sources constituted the minor ecological corridor network. The area around the research area and 60% of the center of the research area was a blind zone of ecological nodes where ecological construction should be enhanced significantly. Newly increased ecological lands were distributed mainly around water bodies, secondarily around greenbelt and scenic areas, and sporadically around forests. The research results provide a scientific foundation for ecological environment protection and urban planning for the central part of the city.