Abstract:Small mammals were trapped using snap-traps in five different pasture and forest regions to investigate the effect of habitat complexity on species diversity of small mammals. In total, 128 individuals were captured, comprising seven species of rodents, of which, Apodemus agrarius was the most commonly. The captured species were not evenly distributed along habitat gradients, which reflected the selection orientation of small mammals to different habitats. Analyses of richness and diversity of small mammals showed that trapping success, species richness and biomass of small mammals have a significant positive correlation with the diversity or heterogeneity of herbage but not with the whole vegetation heterogeneity. This indicated that the coverage and richness of herbage have a higher influence on the spatial distribution and community structure of small mammals. However, the diversity of small mammals had no similar relationships with the diversity or heterogeneity of herbage. Large quantities of small thickets in shrub and forest-shrub regions enhanced the diversity of small mammals. We concluded that the composition of small mammals is related to the complexity of habitats, while the effect of each vegetation type to the biomass and diversity of small mammals is not equal. The influence of herbage on small mammals is largest, while that of shrubs is the second, and trees has the smallest contribution, sometimes even a negative influence on the diversity of small mammals.