Abstract:Green space plays a great role in improving environment, maintaining the balance of ecosystem and promoting low-carbon city construction. So the study on ecological effect of green space becomes significant to green space planning & construction and ecosystem service enhancement. Models based on ArcGIS and ArcVIEW platforms like CITYgreen and i-tree have been widely applied in ecological effect study, especially CITYgreen model application in Shenyang, built-up area of Beijing, Beijing Olympic park, Nanjing, Shanghai Outer Ring Green Belt, Hangzhou and Shenzhen. Based on CITYgreen Model and the TM image analysis of 1987, 2000, 2004 and 2008, in three spatial scales including large scale (the whole area within Outer Ring Rd. of Shanghai), middle scale (districts within Outer Ring Rd. of Shanghai) and small scale (towns & sub-districts within Outer Ring Rd. of Shanghai), the annual carbon storage and air pollution removal ecological effect were calculated, with the large scale results: 167.2 million yuan in 1987, 85.5 million yuan in 2000, 81.6 million yuan in 2004 and 9.7 million yuan in 2008. Then the comparative analysis was done with basic statistics and the Geostatistical Analyst of ArcGIS. The results showed that: (1) In large scale, from 1987 to 2008, overall ecological benefit declined because of the encroachment of urban construction. Although many measures to green space construction have been taken in Shanghai City, the situation within the Outer Ring Rd. still calls for much more efforts; (2) In middle scale, two parts of analysis were done including all the 14 districts and the central 6 districts and the results showed that ecological effect of different districts have different range and variation trend; ecological effect of the outer districts keeps on higher level but changes heavily and the central were always in a low state. Although some measures about building green space have been brought up, the amount of the study area is still decreasing. In addition, most of the increased green space focuses on landscape and recreation function, which leads to the loss of ecological benefit; (3) In small scale, based on Kriging, with surface fitting analysis, the central area had a brief rally during the overall decline trend, especially in the period of 2000 to 2004, due to the green-built measures conducted by Shanghai Municipal Government. Besides, stain chart shows the ecological effect change of every towns and sub-districts, which complements the result of large and middle scale result. There exist differences and connection among study in three spatial scales and from three scales, results of different aspects were presented, which means a lot to the detailed green space planning and construction. Through all the data analysis, this study on ecological effect of green space in Shanghai will get perfection and some scientific basis which will be provided as well for green space planning of large cities like Shanghai. Of course, there are still much more scientific issues to be solved, like the accurate carbon storage of urban green space and the relative questions about carbon sink forest in urban area have become the hottest issue in this field. The results of this study can be the stepping stone of scientific researches in future.