Deep-seated carbon could be transported from Earth s interior into atmosphere by volcanic activities, which play an important role in geologic carbon degassing. In addition to volcanic eruptions, quiescent volcanoes could also release large amount of magmatic CO_2 into atmosphere. Therefore, quantitative studies on the contribution of volcanic activities to rising of atmospheric CO_2 concentration are critical, especially in the context of global warming. The fluxes of greenhouse gases released from typical volcanic fields (i. e. Changbaishan, Tengchong, Wudalianchi and Yangbajing) in Chinese Mainland are estimated by closed chamber method, gas and water chemistry methods, etc. The total greenhouse gases (referring mainly to CO_2) flux of these typical volcanic fields is 8. 13 * 10~6t·a~(-1), taking up about 6% of the total CO_2 flux from global volcanoes. In comparison with Pacific tectonic domain, the fluxes of greenhouse gases from volcanic field associated with Thethys tectonic domain are higher. In addition, volcanic gases from Thethys tectonic domain are characterized by higher degree of crustal contamination than those of Pacific tectonic domain, indicating different tectonic settings and mechanisms of magma evolution between oceanic subduction zone and continental subduction zone.