Abstract:Soil fauna is the important composition in secondary forest ecosystems. As one of the most important factors, vegetation type plays a critical role in influencing the composition and vertical distribution of soil fauna. Aiming to survey the impact of different forest types in secondary forests on composition and dynamics of macro- and meso- soil fauna, macro- and meso-soil fauna within five major forest types of secondary forest ecosystems was investigated in 2007. There were 36210 in total macro- and meso- soil fauna found in the investigation, which belonged to 2 phyla, 8 classes and 32 orders. The dominant groups were Acariformes and Collembola. The results showed that: (1) the fluctuation of groups and individuals in planted forest stands was much greater than that in the secondary forest stands, which indicated that habitats of secondary forest stands were more stable for soil fauna than those in planted forest stands; (2) the biomass of macro- and meso soil fauna in July reached the maximum, except larch planted forest stands and (3) biodiversity index of macro-and meso- soil fauna reached the maximum in September, except Manchurian walnut forest stands. The above results indicated that fluctuation of groups and individuals of soil fauna in secondary forest stands was less fluctuant and more diverse than those in planted forest stands.