Soil microbes are the most important driver for the biogeochemical processes,with particular taxon associated with some unique functions.The rhizosphere function assemblage may be determined by community composition.In this study,we constructed special rhizoboxes with root chamber(RC)planted with Paspalumnatatum(PN,gramineous)or Stylosanthesguianensis(SG,leguminous).Rhizosphere soils in RC and in the near(Rn,0-5 mm from RC)or far rhizosphere(Rf,10-15 mm from RC)were sampled,to explore the distribution and determinant of soil functional assemblage.After 3 month of growth,the horizontal distribution of rhizosphere enzyme activity and functional gene expression depended on both the distances from root plane and the plant species.Soil chemical properties drastically changed.DOC content was significant higher in SG soil.Soil N cycle was significantly affected,while soils from PN were more vulnerable than SG.AvailableKcontentwasmuchdifferent in thefollowingorder:Rf>Rn>RC.Both total bacteria and fungi biomass(PLFA)significantly increased in RC than Rn or Rf regardless of plant species.Both plant species and distance significantly affected(two-way ANOSIM).The chemical-property constrained model was significant(P=0.013,Monte Carlo test),whereas the community-composition-model was not(P=0.089).The rhizosphere function significantly correlated with the soil chemical property(P=0.001,Mantel test)but not the community composition.This suggested that soil functional profiles were determined more possibly by soil chemical properties than by microbial community composition.