Anthropogenic nitrogen (N) deposition significantly affects soil microbial biomassand extracellular enzymatic activities (EE A). To date, numerous studies haveemployed single N addition (mainly in inorganic N) works in reporting influences ofN deposition on soil microbial biomass and EEA during litter decomposition in forestecosystems. As natural atmospheric N deposition is a set of complex compoundsincluding inorganic N and organic N, the research on the influences of mixed Nfertilizations on soil microbial biomass and EEA have an important scientific value,but the related reports were very few.