Abstract: Carbon fixation and oxygen release is an important eco-service of natural ecosystems, and mean significantly to global climate change and development of human society. Beijing-Tianjin-Hebei region was cited as the study area, of which the net primary productivity (NPP) and carbon emission and oxygen consumption data were collected for analysis of net capacity of the ecosystem of the region providing eco-service of carbon-fixing and oxygen-releasing (CFOR) at the pixel scale and provision-reception relationship of the eco-service, with the aid of the ArcGIS platform, and theories and methods of the "Provision-Reception " domain. Results show that:(1) The net CFOR eco-service capacity of the region exhibited a declining trend from northwest to southeast, with the highest values mainly distributed in Chengde, east Zhangjiakou, northwest Beijing, north Qinhuangdao, and northwest Baoding, and negative values in the core economically developed and densely populated areas in most of the prefecture-level cities and above; (2) According to the value of the CFOR service, the areas positive in net eco-service value accounted for 64.32% of the region in land area, while the areas negative in the value did for 35.68%; but the former was inadequate in supply capacity, whereas the latter high in demand of the eco-service. As a whole, the studied region is unable to satisfy itself in CFOR eco-service. The eco-service in the region is priced at -0.93 yuan·m^-2·a^-1. (3) The studied area has a total of 64 eco-service provider counties, 33 eco-balance counties, and 82 benefited counties. CFOR eco-service is the highest in Fengning Manchu Autonomous County of Chengde City, reaching 1.01 yuan ·m^-2·a^-1, and the lowest in Heping District of Tianjin City, being -339.46 yuan ·m^-2·a^-1.