1.The relative number of microorganisms and microfloxa in paddy soils is quite different from that in cultivated upland soils and idle field.Among the sporogenous bacteria,Bac.idosus and Bac.megatherium are the predominant species,while Bac.subtilis-mesentericus is comparably less.2.Penicillium、Aspergillus and other genera of fungi are usually present in paddy soils,and Tuberculina,Emericeldopsis and Sporormia(?) are the special genera also frequently occured.Perhaps these fungi have a better adapt ability to live under a less aerobic condition.3.The composition of soil microflora varies according to soil fertility.Fertile soils have a relatively high percentage of Penicidlium-Asymmetrica,and the rate of ammonification and cellulose decomposition are much intense than the Monoverticillata serves.