To inquire into the effects of different management treatments on carbon balance of the coastal saline soils, field maize-wheat rotation experiments were conducted to study C balance in different management treatments. There were 6 treatments which were ① conventional tillage (CK); ② application of organic fertilizer (OF); ③application of nitrogen fertilizer (NF); ④ application of straw (S); ⑤ application of organic fertilizer and straw (OF + S); ⑥ no tillage (NT). It turned out that treatments of S and OF increased the emission of soil CO_2, and the average CO_2 efflux of NT released a quantity to a minimum, the average rate of CO_2 emission in different treatments showed as follows: OF + S>S>OM>NF>CK>NT. After crops harvested, soil organic carbon content increased in each measure, the largest were OF and NT measures, NF did not significantly raise the content of soil organic carbon. After the experiment, carbon input were higher than carbon output in each measure, were all the net carbon input, it showed the strong characteristic of carbon sink. The C net inputs of S and OF measures were significantly higher than CK, these would effectively slow down the global climate change caused by the farmland soil CO_2 emissions.