The fluxes of dichloromethane (DCM, CH2Cl2) and 1, 2-dichloroethane (1, 2-DCA, CH2CH2Cl2) were seasonally measured using static flux chambers from April 2004 to January 2005 along an elevational gradient of a coastal salt marsh in eastern China. To estimate the contribution of higher plants to the fluxes, plant aboveground biomass was experimentally removed and the flux difference between the treatment and the intact was tested. In addition, the fluxes were analyzed in relation to soil and weather conditions. Along the elevational gradient, the salt marsh generally acted as a sink for the compounds in the growing season (from April to October), and the maximum negative flux occurred at the cord\|grass marsh for DCM and at mudflat for 1, 2-DCA. In the non\|growing season (from November to March), the vegetated marsh was a source of DCM and 1, 2-DCA. However, because of the lack of extensive sampling in the non\|growing season, it is hard to determine whether the marsh under study is a source or sink for DCM and 1, 2-DCA. Comparative analyses showed that the higher plants acted as an important sink for DCM and 1,2-DCA in the growing season, but a net source for them in the non\|growing season, even during the frozen time.The mechanism responsible for the release and removal processes of plants is not clear. The fluxes of DCM and 1, 2-DCA were positively correlated to light intensity, soil dissolved salt, soil organic matter, and TN content, but were negatively correlated to soil temperature, sulfate content, and their ambient concentrations. This suggests that the net consumption of DCM and 1, 2-DCA observed in the study marsh may result from the high ambient concentrations and enriched soil organic matter that resulted in anoxic sediments.