To study the diversity and community structure of filamentous fungus in riceoilseed multiple cropping fields with convertionaltillage(CT) and  notillages(NT). Microorganism population analysis were studied based on ITS sequences analyzed by MiSeq. The results showed that 221 105 vaild sequences was obtained, it covered 1 356 OTU, 7 phylums, 121 families and 230 generaes; The index analysis showed that the relative abundance and community diversity of the NT samples were slightly higher than that of the CT samples. On the phylums level, the relative abundance of Ascomycota in NT samples was lower than that in CT and the zygotes and basidites was higher than that in CT; The vaild sequences of Carpoligna、Trametes、Filobasidium、Mortierella in NT samples was higher than that in CT and Chaetomium、Podospora、Thanatephorus was lower than that in CT on the generaes level. The physical and chemical factors of soil organic matter determination showed that the total nitrogen and available potassium content in NT samples were higher than those in CT samples. There are indifferences filamentous fungus population structure in riceoilseed multiple cropping fields with convertionaltillage(CT) and riceoilseed multiple cropping and notillages(NT).The composition and abundance of flora has a certain effect on the soil physical and chemical factors.