Abstract: In this study, we investigated changes in metabolic profiles of germinated seeds of S. tonkinensis in response to Ca²⁺ stress by using an untargeted metabolomics approach. Results suggested that seeds of S. tonkinensis played different metabolic strategies in response to different concentrations of Ca²⁺ stress during germination. There were 36 differential metabolites of germinated seeds under 0 mmol/L CaCl₂ and 50 mmol/L CaCl₂, 14 differential metabolites of germinated seeds under 0 mmol/L CaCl₂ and 100 mmol/L CaCl₂, 24 differential metabolites of germinated seeds under 50 mmol/L CaCl₂ and 100 mmol/L CaCl₂. These metabolites were mainly involved in isoflavonoid and flavonoid metabolism, lipid metabolism, and organic acids metabolism.