Soybean (Glycine max (L.) Merrill) is one of the most important crops globally. Its seeds are widely used in food processing due to their high protein and lipid content, along with bioactive compounds beneficial to human health, such as isoflavones and γ-aminobutyric acid (GABA). However, soybeans also contain anti-nutritional factors like phytic acid (PA), trypsin inhibitors, and lipoxygenase enzymes. This study investigated the effects of germination temperature and duration on GABA accumulation, PA degradation, and changes in chemical composition (protein, lipid, and ash content) in Xuan Lang Son, a local soybean variety in Vietnam. Germination significantly increased GABA content, with the highest value (6.37 mg/g dry weight) observed at 30 °C for 36 hours. Conversely, PA content decreased steadily, reaching the lowest level (29.68 mg/g) after 48 hours at 30 °C. Protein content peaked at 36.54% (dry weight) after 48 hours at 28 °C, while lipid and ash contents declined under all conditions, likely due to metabolic consumption and leaching. Statistical analysis showed that both temperature and duration significantly influenced most parameters, with a notable interaction effect on protein content. These results suggest that controlled germination at 28 – 30 °C for 36 - 48 hours is an effective strategy to improve the nutritional and functional quality of soybeans. This approach has potential applications in the development of traditional and functional soybean-based foods enriched with health-promoting nutrients