Abstract: Soil labile organic matter is sensitive to farmland management and climate change,and is often used as an indicator of soil quality change,which has become a research hotspot in soil ecology and environmental soil science.In this paper,we systematically reviewed the classification methods of soil labile organic matter,including the classification of physical components (light organic matter,particulate organic matter,macro-aggregate organic matter,acid and alkali extracted organic matter,and dissolved organic matter),chemical components (acid hydrolyzed organic matter and readily oxidized organic matter),biological components (microbial biomass carbon and nitrogen,and potentially mineralizable carbon and nitrogen) and combined group components (free aggregate organic matter,physically protected organic matter,and free labile organic matter).The sources,typical quantities (proportion in soil total organic matter),properties and significance of different components were analyzed,and the research history,functions and influencing factors of related components were commented.Finally,we discussed the integration application and research progress of soil labile organic matter methods,and put forward the possible technical approaches to supplement and verify the uncertainty and difficult comparison determined by soil labile organic matter.The paper would provide theoretical basis and technical support for scientifically analyzing the role of soil labile organic matter in soil quality.