Sanjiang Plain is the biggest wetland in China, however through about 50-year development, the wetland area reduced to 959 000 hm2 while the cultivated area increased to 5 569 000 hm2 in 2005, which caused obvious influences on the distributions of soil organic carbon and total nitrogen. So using the data of 1 400 typical profiles (53 representative profiles in Sanjiang Plain), we analyze the distributions of soil organic carbon and total nitrogen under different land uses in the northeast of Sanjiang Plain. The mean contents of soil organic carbon and total nitrogen at 0-20cm and 20-100cm soil depths of typical cropland are 22.7g/kg, 1.84g/kg and 13.0g/kg, 1.08g/kg respectively, however, the distributions of soil organic carbon and total nitrogen at 0-20cm and 20-100cm soil depths under different soil types and crops do not show significant differences (p＞0.05). Compared with the corresponding data collected in the 2nd soil survey in 1980s, both soil organic carbon and total nitrogen show the declining tendency at 0-20cm soil depths and the increasing tendency at 20-100cm soil depth.