Fresh flavor is the key factor of the taste quality of vegetable soybean， and its formation is closely related to the organic acids. It is of great practical significance to analyze the synthesis mechanism of organic acids in quality improvement of vegetable soybean. In this study， the soybean hairy root system was used to explore the functions of candidate genes GmALMT8， GmIF7GT5 and GmAP， which are significantly related to malic acid content， in regulating malic acid content. The transcripts of GmALMT8 gene and the content of malic acid in GmALMT8-OE hairy roots were significantly higher than those in control hairy roots without inserts， while the content of malic acid in GmIF7GT5 and GmAP transformed hairy roots had no significant change.In view of the reported malic acid transport function of ALMT family genes， it is speculated that GmALMT8 gene in soybean may have a similar function and play an important role in regulating malic acid content. In order to verify whether the change of malic acid content in GmALMT8-OE hairy roots is caused by the change of GmALMT8 gene expression， this study overexpressed GmALMT8 gene in Arabidopsis thaliana by dipping flower method. Similar to the results of malic acid determination in positive hairy roots， overexpression of GmALMT8 significantly increased the malic acid content in seeds of T₂ transgenic Arabidopsis thaliana.These results approved that soybean GmALMT8 gene had biological function in regulating malic acid content， which enriched the theoretical research of soybean organic acid and provided reference value for high-quality breeding of vegetable soybean.