Abstract: Soil organic matter (SOM) is an important component of soil.It can provide various nutrients for plants,and thus maintain the stability of the soil ecosystem.SOM is the largest and most active carbon pool in the surface terrestrial ecosystem,and its small fluctuation in soil affects the source and sink of the global carbon pools.The territory of vast China is with huge carbon stock,which plays a significant and important role in global carbon sink.Therefore,further researches concerning the quantity,fraction and chemical structure of SOM in the context of global climate change will be of great significance in evaluating the carbon cycle in the whole terrestrial ecosystems.In this review,we divided the study area into six representative regions,namely,the Northeast region,North China,Northwest region,Southeast region,Southwest region and the middle region,and compared the characterization of the quantity,fractions and chemical structure of SOM among the regions.Factors influencing the changes were further illustrated.It is proposed that the comparisons of the quantity,fractions and chemical structure of SOM in the main regions of China would provide references for future SOM research and managements in various regions of China.