Abstract: Soil heterotrophic respiration is an important part of forest carbon cycle; therefore, studies on this topic will help to explore the causes for global climatic change. Soil heterotrophic respiration of 15year old metasequoia plantation was investigated in silting coastal area of northern Jiangsu province and soil CO2 efflux was measured in situ with the static alkali absorption method. Results showed that soil heterotrophic respiration rate of the metasequoia plantation between February and October varied from 4.72 to 12.87 g/(m2·d), the largest soil respiration rate occurred in July and the smallest appeared in February. Temperature was the limiting factor to soil respiration. The Q10 values were calculated with forest air temperature and the soil temperature of 2, 5, 10 cm soil depth were 1.00, 1.59, 1.55 and 1.54, respectively. These results are important to future studies on soil respiration of silting coastal plantations and provide basic data for the further research in carbon circle.