Abstract: The research aimed to investigate the effects of various nitrogenous compounds on seed germination of Medicago sativa L. under basic Na2CO3 stress. Six nitrogenous compounds were used in the experiment, each at eight concentrations. Seed germination percentage was calculated. The result showed that none of the nitrogenous compounds could significantly alleviate the inhibitory effect of 25 mmol/L Na₂CO₃ on seed germination of M. sativa. Several treatments approached or exceeded the control. Treatments with all tested compounds except NH₄H₂PO₄ at higher concentrations decreased the germination significantly. Early germination, recovery germination and total germination under treatment with 80 mmol/L NH₄H₂PO₄ (pH 6.63) were higher than those under the control, not significant statistically. These results further indicated that stress effect of salt was closely related with pH. More extensive trials were needed to explore the possibility of ameliorating soil salinity based on alkaline decrease in improving crop production in saline-alkali soil.