An experiment was conducted in the laboratory by cultivating the herbages for highway slope protection in pots to assess the effect of different soil matrix on the growth performance of the plant community.The results indicate the growth rate of the herbages increased with the increasing contents of sludge compost in the soil matrix(p<0.05),while the thickness of soil matrix did not affect the growth rate(p>0.05).Increased sludge compost in soil matrix can benefit the height,density and cover of plant community(p<0.05),and increased thickness of soil matrix can promote the height,density and cover of plant community(p<0.05).Increased sludge compost can promote the aboveground and belowground biomass of plant community(p<0.05),while reduce the root and shoot ratio of plant community.With increasing thickness of soil matrix,the aboveground and belowground biomass of plant community increased but the root and shoot ratio of plant community decreased(p<0.05).To promote growth and cover of the plant community and increase their capacity of controlling soil and water on the slope,right amount of sludge compost should be added in the soil matrix and enough thickness of soil matrix should be kept.