Abstract: In order to screen the soybean rhizobium with high compatibility and strong nitrogen fixing ability with the main vegetable soybean varieties Liusi, Cuilyubao and Tiedou in Hainan Province. In this study, 8 strains of rhizobium isolated from different ecological regions were selected for culture and screening using low nitrogen vermiculite substrate cultivation method. Stem and leaf dry weight, leaf SPAD value, root dry weight, root nodule dry weight, root nodule number and other indexes were determined, and structural equation model analysis and correlation analysis were conducted to evaluate the effects of different rhizobia on the growth of vegetable soybean. The results showed as follows:（1）There were significant differences in the growth promotion effects of different varieties of vegetable soybean inoculated with different rhizobia. The effects of inoculation with CCBAU 25435 on the stem and leaf dry weight, leaf SAPD value and other growth indexes of vegetable soybean were significantly increased by 80% and 112% compared with those without inoculation with rhizobia. There was no significant difference or even slightly better than the highly effective nitrogen-fixing rhizobium USDA 110 widely inoculated internationally.（2） Leaf SPAD value, root dry weight and nodules dry weight had significant positive and direct effects on the formation of shoot dry weight, among which leaf SPAD value had the highest influence weight, and nodules number indirectly promoted the formation of shoot dry weight through the first three factors.（3） The number of nodules and dry weight of nitrogen-fixing rhizobia of medium-effective and high-efficient nodules were significantly higher than those of ineffective bacteria, while the dry weight of unit nodules of efficient bacteria was significantly lower than that of medium-effective bacteria. This study revealed the relationship between root nodule traits and plant growth. The root nodule biomass was not strictly positive correlated with the nitrogen-fixation promoting effect, and the nodule number could better reflect the nitrogen-fixation promoting effect than the dry weight of the nodules. The screened efficient nitrogen-fixing rhizobia provided high-quality rhizobia resources for the development and application of rhizobia agents in Hainan area. The highly efficient nitrogen fixing rhizobia screened in this study provided high-quality rhizobia resources for the development and application of rhizobia agents in Hainan.