Abstract: This paper calculates the carbon storage of farmland shelterbelts in the plain area of China during 20012005 using the method of biomass expansion factor continues function. The results showed that: 1) the carbon storage of plain farmland shelterbelts in China increased yearly, and the increasing rate was higher than that of forest carbon storage nation wide; 2)the descending order of carbon storage of six plain areas in China was eastern China, northeastern China, northern China, central south China, northwestern China, southwestern China, and the carbon storage of farmland shelterbelt among provinces in each area varied; 3) comparing the carbon storage of each tree species in plain farmland shelterbelts, it was found that poplar was the dominant tree species, whose carbon storage occupied 90% of the total of plain farmland shelterbelts in China; 4) the carbon density of all tree species was rising yearly during 20012005, and the descending order of carbon density for tree species was Eucalyptus spp., Poplus spp., Casuarina spp., Metasequoia spp., Pinus massoniana.