Abstract: The purpose of the experiments reported here was to determine the effects of inoculating rhizobia strain NM353 on the growth and N use between intercropped faba bean(Vicia faba L.cv.Linxia Dacandou) and wheat(Triticum aestivum L.cv.Long 17),and to quantify the contribution of N fixation of faba bean to the companion crop wheat.The root barriers were used to assess the contribution of interspecific root interaction to crops' growth via pot experiment.Accordingly,the pots at the volume at(π×72×15)cm3 were separated into two compartments,either by a solid barrier(plastic sheet) to prevent root contact and N movement,by nylon meshes(30 μm) to prevent root contact,but allow N exchange, or no root barrier between the compartments to allow root interaction.Thereafter,faba bean was inoculated with rhizobia strain NM353 either under the condition of N application and non-N application in three different root barriers.The results showed that wheat growth was enhanced without root barrier no matter with N or without N,leading to higher biomass and N acquisition than those with both solid barrier and mesh barrier.Root interaction did improve the growth of wheat,and so did N application.Faba bean growth was not affected by root barriers with NM353 inoculation but affected without NM353 inoculation.Rhizobia strain NM353 inoculation did improve the growth of faba bean with(solid) barrier,while N reduces the growth of faba bean.Obviously,the inoculation effects on faba bean in intercropping differed in root barriers and N application,but the growth of faba bean was enhanced on the average at 12% compared with that without innoculation.The biomass of faba bean was increased 15%,16% and 5%,respectively with respect to the three root barriers under N application,and accordingly the N acquisition of faba bean was increased at 17%,9% and 12%,respectively.Only when interspecific roots interaction occurred could wheat benefit from inoculating rhizobia strain NM353 on faba bean.The growth of wheat without root barrier was improved by inoculating NM353 either with N or not,leading to higher biomass and N acquisition.Under N application,the biomass of wheat was enhanced by 13% compared with that without inoculation,and N acquisition by 22%.Thereby,the feasible way existed in inoculating appropriate rhizobium strain for intercropping that would improve N nutrition of both cereal and legumes.