AbstractSoil biota is an important gene library and forms a major part of global biodiversity. Soil biota drive the cycling of soil C and N biogeochemistry and influence trace gases metabolism. Soil microorganisms exercise direct effects on trace gases metabolism. Fungi, methanogens, CH₄-oxidizing bacteria, nitrifiers, and denitrifiers are the key types of communities regulating trace gases metabolism. Fungi often dominate degradation activities in litter due to their large individual body and strong enzyme chemical degradation abilities. “Oxic-anoxic” interfaces are active habitats for microorganisms and easily influence trace gases metabolism. “Organic-inorganic” layers, the rhizosphere of hydrophytes, and soil faunal intestines are the typical interfaces for trace gases metabolism. Soil fauna are pioneers for litter degradation and show indirect effects on trace gases metabolism, and these effects are very important. Arthropods (e.g.termites) and annelid (e.g.earthworms) metabolise CH₄ and N₂O, respectively. Since the soil ecosystem is complicated, it is necessary to develop an integrated technique comprising microbiology, stable isotope and molecular biology for studying soil biodiversity and its effects on trace gases metabolism. Research on soil biodiversity and its relationship to trace gases metabolism urgently needs to be developed in China.