An experiment was carried out in south of Anhui province to study soil mierobeeategories and relative numbers of four kinds soil system (bottom- land,alluvium,paddy clay andalluvon sandl) in tobacco life cycle.The main re- suits are as follows:no matter in rooted omon - rOOted soil,the bacteria,fungi and aetinomycetes are main categories which gross numbersare more than 95% in all soil microbe mounts.During the flue--cured tobacco life cycle,thenon--root- ed micrObe gross number was less than the rooted' S,...