Ecological space quality is a key indicator for characterizing the optimal degree of natural environment and the suitability of ecosystem services to society. Based on high-quality development concept of territorial space and Wetland Rapid Assessment Procedure (WRAP),an evaluation framework of ecological space quality was set up, including habitat naturalness, landscape stability, environmental suitability and management regulation, which was applied to 226 field sites in Nanjing riverside area. The results from field assessment and Principal Component Analysis (PCA) showed that the comprehensive ecological space quality was generally with significant differences in land use types and spatial distribution, which was closely related to human activities. In particular, the grade number of habitat naturalness was evenly distributed with spatial autocorrelation among field sites. However, approaching to the Yangtze River, the scores of landscape stability had an ascending effect with the grade range of " high at both sides and low in the middle". Both environmental suitability and management regulation had good performance, in which sites with high management level were concentrated in high urbanization area. In addition, there existed significantly negative correlation between the rapid assessment results and landscape development intensity index (LDI) (R²=0.56, P<0.01), which was selected to validate our research. Furthermore, other studies focusing on the Nanjing section of the Yangtze River were also corresponded to our results, indicating that rapid assessment method could reflect the ecological space quality of Nanjing riverside area objectively. Despite simple, efficient and low-cost, it is still necessary to improve our method in the expansion of index content, the reduction of operational subjectivity, mathematical statistics model of differential weighting and multi-period dynamic assessment. A uniquely ecological environment integrating mountains, rivers, forests, cropland and islands is inseparable from the relevant policies and special plans, which also reveals various quality problems, such as human destruction, low land use efficiency and single management mode. The assessment results could have certain theoretical and practical value for the implementation of the Great Protection Strategy of the Yangtze River coastline and territorial space planning.