Abstract:The distribution of the soil microorganisms in Chinese fir plantation watershed in Huitong varies with different ages of stand．With the increment of the stand age，the bac-teria show a decrease tendency，actinomyces and fungi show an increse tendency．Most nitrifying bacteria occurs in the 8-year-old Chinese fir plantation，while least in the 30-year-old plantation．The results of the studies indicate that the quantities distribution of the soil microbes varies with forest eco-environment．They have important effects on the soil fertility and tree nutrient．