Ecosystem respiration contributes greatly to carbon emissions and losses in coastal wetlands. To gain a better understanding of gaseous carbon loss from a coastal wetland covered by seablite (<i>Suaeda salsa Pall.</i>) and to evaluate the influence of environmental factors on ecosystem respiration, a multi-year in-situ experiment was carried out during the growing season of 2012 through part of 2014. By partitioning total carbon dioxide (CO<sub>2</sub>) flux into soil respiration (<i>R<sub>soil</sub></i>) and plant respiration (<i>R<sub>p</sub></i>), we found that during mid-summer, ecosystem CO<sub>2</sub> respiration rates (<i>R<sub>eco</sub></i>) were within the range of 844.5 to 1150.0 mg CO<sub>2</sub> m<sup>−2</sup> <sup>−1</sup>, while <i>R<sub>eco</sub></i> was as low as 31.7 to 110.8 mg CO<sub>2</sub> m<sup>−2</sup> h<sup>−1</sup> at the beginning and the end of growing seasons. Aboveground <i>S. salsa</i> plant material comprised 79.1 % of total biomass on average, and <i>R<sub>p</sub></i> dominated <i>R<sub>eco</sub></i> during inundated periods. It is estimated that 1 gram of soil-emergent <i>S. salsa</i> biomass (dry weight) could produce approximately 1.41 to 1.46 mg CO<sub>2</sub> per hour during mid-summer. When water level was below the soil surface, soil microbial and belowground root respiration (<i>R<sub>s+r</sub></i>) was exponentially correlated with air temperature. Based on our observation, an empirical model was developed to estimate system respiration of the <i>S. salsa</i> marsh in the Liaohe River Delta, Northeast China. This model can be applied for regional carbon budget estimation purposes from <i>S. salsa</i> wetlands throughout Northeast China.