土壤微生物的种类和多寡能够反映土壤质量。本文对皇甫川流域油松林和沙柳灌丛的土壤微生物 (包括芽孢型细菌、放线菌 )进行培养、分类、分析、研究。结果表明 :两种不同林地的土壤微生物区系组成、种类、多寡均不同 ,且油松林地大于沙柳灌丛 ,所以 ,油松林的土壤质量要比沙柳灌丛的土壤质量高 Soil microbial species and quantity can reflect the soil quality. In this paper, soil microorganisms (including spore-forming bacteria and actinomycetes) of Pinus tabulaeformis and Salix shrub in Huangfuchuan watershed were cultured, classified, analyzed and studied. The results showed that the composition, species and amount of soil micro-flora in two different woodlands were different, and the Pinus tabulaeformis forests were larger than Salix shrubs, so the soil quality of Pinus tabulaeformis forest was higher than that of Salix psammophila