Abstract: The American Ginseng ,as the study objects, which grew in different years in Jiling and Beijing, were studied on Dynamics of Soil Microorganisms by separating, culturing, counting and identifying the edaphon among soil of American Ginsengs. As the result showed: Compared to American Ginsengs growing in different years, the result showed that the amount of edaphon in American Ginsengs’ rhizosphere became larger and the soil physcial and chemical properties changed in different degree .Moreover, the major advantages of the occasion of fungi populations of American ginseng rhizosphere soil were indentified. And The group and quantity of pathogen (Alternaria sp.) and antagonistic bacteria (Thrichoderma sp.) in rhizosphere soil of American ginseng all increased as time passing by.