Rice bean （Vigna umbellata （Thunb.） Ohwi & Ohashi） is an underutilized legume crop with considerable potential for nutritional and health-promoting applications， highlighting its promising prospects for future development. In this study， we quantified four major nutritional components—including protein content， starch content， total flavonoid content （TFC）， and total polyphenol content （TPC） —in 410 rice bean core accessions. The protein content ranged from 15.9% to 28.2% （mean： 21.0%）， and starch content varied between 40.0% and 53.7% （mean： 45.8%）. Meanwhile， TFC and TPC ranged from 1.34-7.39 mg RE/g （mean： 4.10 mg RE/g） and 0.80-2.90 mg GAE/g （mean： 2.19 mg GAE/g）， respectively. Based on these results， 34 representative accessions were selected for comprehensive untargeted metabolite profiling analysis， which identified 607 metabolites in 12 major categories. Variations in key metabolite classes—such as flavonoids， amino acids and derivatives， alkaloids， and terpenoids—were observed among accessions from different geographic origins. Specifically， accessions from China and Myanmar exhibited the higher flavonoid abundance （19.0% and 19.7%， respectively）， while those from Thailand and Laos showed higher levels of amino acids and derivatives （20.1% and 18.3%， respectively）. This study provides a valuable dataset to support the evaluation， exploration， and breeding-oriented utilization of high-quality rice bean germplasm resources.