CH4 and N2O are important atmospheric trace gases,which play significant roles in the global warming and atmospheric chemistry,and the global oceans are net natural sources of atmospheric CH4 and N2O.Although coastal regions only occupy a small part of the world ocean area,they appear to be responsible for a large part of the oceanic CH4 and N2O emissions.Therefore,studies on the biogeochemistry of dissolved CH4 and N2O in coastal waters will be helpful to estimate the contribution of oceanic emissions to the atmospheric CH4 and N2O on a global scale,and to predict the influence of oceanic emissions to the global climate.