【Objective】Arbuscular mycorrhizal(AM)fungi have the potential for biocontrol of soil-borne diseases, e.g., pepper(Capsicum annuum L.)Phytophthora blight. However, the mass production and wide application of AM fungi have not been achieved due to the difficulties associated with in vitro cultivation. Therefore, it would be of great significance if the disease suppression function of soil indigenous AM fungi can be exploited.【Method】In the Pepper Science Park of Shizhu County, Chongqing city, plot experiments in a facility shed were carried out to investigate the effects of intercropping with maize(Zea mays L.)on indigenous AM fungal propagation and pepper Phytophthora blight suppression.【Result】Compared with the control(i.e., mono-cropping of pepper), intercropping with maize significantly increased not only the root mycorrhizal colonization rate of pepper, the rhizosphere AM fungal abundance, and soil phosphatase activity, but also the total nutrient(N, P, and K)acquisition amounts by the two crop species per plot. In contrast, intercropping with maize significantly decreased not only the incidence and severity of pepper Phytophthora blight but also the P acquisition amount and the fruit biomass per pepper plant. Compared to the treatment with the same row distances as control(SRD), the intercropping system which had the same ridge widths as control(SRW)and a relatively higher planting density, induced significantly higher(i)root mycorrhizal colonization rates with both crops, (ii)maize yield per plot, and(iii)total nutrient acquisition amounts by the two crop species per plot. Furthermore, the pepper Phytophthora blight incidence was significantly lower in the intercropping system with SRW than with SRD. 【Conclusion】In facility sheds, intercropping with maize may enhance the suppression of pepper Phytophthora blight by soil indigenous AM fungi via promoting their propagation and thus colonization on pepper roots. Also, the intercropping system with SRW has a relatively higher economic benefit compared to SRD.