【Objective】In this study, responses of soil nematodes community in composition and diversity to interplanting of A. lancea in monocultured peanut soil were explored and mechanisms of the effects analyzed.【Method】Soil samples were collected from a 10-year monocultured peanut field for a pot experiment, which was designed to have two treatments, i.e. monocropping of peanut and interplnating of A. lancea with peanut. At the maturing stage of peanut, population of nematodes in rhizosphere soils of the peanut and A. lancea was measured, separately, and composition and diversity of the nematode communities were analyzed.【Result】Results show that in the treatment of interplanting, the peanut significantly increased in plant height, main root length, straw yield and pod yield and the nematodes changed in density, diversity and community structure. Interplanting significantly decreased the population of nematodes in the rhizosphere soils of both peanut and A. lancea, especially the number of plant-parasitic nematodes, which used to be the dominant group. Interplanting significantly enhanced the relative abundance of bacterivores, fungivores, and predators/omnivores, but significantly inhibited plant-parasites in the rhizosphere soils of peanut. Analysis of nematode ecological indices shows that the interplanting treatment was more stable in soil ecosystem, and it raised Shannon-Wiener index (H') and evenness index (J), and lowered dominance index (λ) of the nematodes in the rhizosphere soil of peanut, while, increasing evenness index (J) and altering little diversity index of the nematodes in rhizosphere soil of A. lancea. Interplanting also significantly increased Wasilewska index (WI) and maturity index (MI) of the nematodes in the rhizosphere soil of peanut, while reducing plant parasite index (PPI) of the nematodes in the rhizosphere soil of peanut and affecting little Nematode channel ratio (NCR) of the rhizosphere soil. 【Conclusion】In conclusion, the study has found that interplanting of A. lancea with peanut can increase diversity of the nematodes community, and improve its structure of the nematodes in peanut fields under monoculture, and further on, strengthen ecological function of beneficial nematode and mitigate the obstacle for monocropping of peanut.