Urban green space ecosystem has the functions of gas regulation, harmful gas and dust absorption, and noise reduction, playing an important role in improving urban environment and ensuring human health. These purification services also provide a basis for realizing urban sustainable development. The evaluation of the environment purification service value of urban green space ecosystem in Qingdao City, in combination with the analysis of green space distribution and its construction process under the situation of population increase, could provide a theoretical basis for the urban planning, ecological city construction, and urban green space construction of the City, and for the improvement of its urban environment as well as the sustainable development of the city ecosystem. From 1999 to 2009, the total urban green space in Qingdao had increased from 7005.4 hm² to 16002.8 hm², with the green space per capita increased from 30.20 m² to 58.09 m², public green space per capita increased from 7.35 m² to 14.54 m², green coverage rate of built-up area increased from 35.90% to 43.20%, and the numbers of zoos and botanical gardens increased from 36 to 73. Both the population and the urban green space in Qingdao urban area in 2009 had the characteristics of spatially uneven distribution. Comparatively, the four urban districts (Shinan, Shibei, Sifang, and Licang) had a larger and denser population but a smaller green coverage rate of built-up area and smaller public green area; while the three suburb districts (Laoshan, Chengyang, and Huangdao) had a smaller and sparser population, but a larger green coverage rate of built-up area and larger public green area per capita. Based on the spatiotemporal dynamics of green space in Qingdao from 1999 to 2009, the annual environment purification service value of urban green space ecosystem in the City was calculated by using market value method, production cost method, and displacement cost method, and the results indicated that in 1999-2009, the environment purification service value of urban green space ecosystem in the City increased dramatically from 1.587×10⁸ yuan RMB to 3.491×10⁸ yuan RMB, with the service value per capita increased from 68.42 yuan RMB to 126.73 yuan RMB. In the eleven years, the net increase of the service value was 1.904×10⁸ yuan RMB, with the average annual increasing rate being 10.91%. In the total purification service value, the service value of gas regulation accounted for 49.81%-51.72%, and that of harmful gas and dust absorption and noise reduction accounted for 48.28%-50.19%. The gas regulation service of urban green space had the transferability in locality, which could be compensated by the natural ecosystems out from urban areas, while the service of harmful gas and dust absorption and noise reduction was the one which had no transferability in locality. To intensify the urban green space construction and to enhance the greening level would be the effective measures in improving the urban environment quality and human habitation standard of Qingdao. In methodological aspect, the indices yearly carbon-fixation and oxygen release amounts per unit area of urban green space adopted by Liu Yunlong et al. (2009) were modified, but there still had two aspects that should be modified. First, appropriate methods should be adopted to eliminate the influence of US Dollar exchange rate to RMB on the calculation of yearly carbon-fixation survive value, and the second, the environment purification service value of urban green space ecosystem should be calculated by using the areas of forestland, shrub land, and grassland, if the data could be provided, to obtain more accurate results.