China is a big agricultural country. The research on the carbon sink function of crop production in China’s typical agricultural areas plays an important role in estimating the regional carbon budget and making management policies to tackle climate changing issue. The production of staple crops can be generally reflected by their carbon sinks. The carbon sinks of different crops in the same area differ greatly, and the carbon sink of the same crop also differs in different areas. The national annual reserve of soil organic carbon can be generally embodied in its carbon sink as well. The annual reserves of soil organic carbon in different areas range between –2.07 TgC·y–1 and 19.95 TgC·y–1.