Abstract: In order to explore the mechanism of combined inoculation microorganisms improving coastal saline soil property and plant growth, the effects of different proportion of arbuscular mycorrhizal fungi (AMF) and phosphate-solubilizing fungus (PSF) infection on growth, chlorophyll contents, P-uptake of castor bean and rhizosphere soil pH values, available P concentrations, enzyme activities were assessed in pot experiment. The results showed that soil enzyme activities (i.e., invertase, urease, neutral phosphatase, and alkaline phosphatase) and available P concentrations of soil were stimulated, and soil pH values were decreased by combined inoculation with AMF and PSF. Chlorophyll contents, P-uptake, and plant dry weight of castor bean were also enhanced. The optimal proportion was 28.56:(11.5?105) (number of AMF spores: Ms colony) which have positive effects on saline soil and stimulating plant growth under greenhouse condition. These results demonstrated the potential of the appropriate proportion of arbuscular mycorrhizal fungi and P-solubilizing fungi in enhancing coastal saline soil property and promoting castor bean growth.