Abstract: 【Objective】 This study aimed to investigate the effects of rapeseed root exudates on growth， cadmium （Cd） uptake， and Cd accumulation of rapeseed， thereby providing theoretical basis for revealing the roles in natural remediation of heavy metal pollution of soil. 【Method】 High-Cd-enriched rapeseed variety H38 and low-Cd-enriched rapeseed variety L58 were used as research objects. Effects of rapeseed root exudates on biomass， Cd content， and Cd accumulation of rapeseed were investigated by soil culture pot experiment. Key root exudates of the two rapeseed varieties were screened by untargeted metabolomics technology to further investigate their effects on Cd uptake and accumulation of rapeseed. Scanning electron microscopy-energy dispersive spectroscopy （SEM-EDS） analysis was performed on the rapeseed root samples of rapeseed varieties H38 and L58 treated with oleic acid. 【Result】 Soil culture potting experiments showed that H38 root exudates could increase the biomass， Cd content， and Cd accumulation of rapeseed varieties H38 and L58， but showing no significant effects （P>0.05， the same below）. Rapeseed variety L58 root exudates inhibited Cd content and Cd accumulation of the two rapeseed varieties， and significantly influenced the rapeseed variety L58 （P<0.05， the same below）. The untargeted metabolomics analysis showed that the H38 root exudates of higher relative contents were palmitic acid， oleic acid， and D-leucine， and the L58 root exudates of higher relative contents were oleic acid， palmitic acid， and myristic acid； two metabolites （estradiol and 4-guanidylbutyric acid） with high fold changes were screened out. Addition tests of key root exudates showed that the addition of oleic acid and estradiol could significantly reduce the Cd content and Cd accumulation of rapeseed variety H38， and estradiol could also significantly reduce the biomass of rapeseed variety H38. The addition of D-leucine and 4-guanidine butyric acid could significantly increase the biomass and Cd accumulation of rapeseed variety L58， and D-leucine could also significantly reduce the Cd content of rapeseed variety L58. The addition of palmitic acid could significantly reduce the Cd accumulation of rapeseed variety H38， and significantly increased the Cd content and Cd accumulation of rapeseed variety L58. The addition of myristic acid had no significant effects on the biomass， Cd content， and Cd accumulation of rapeseed varieties H38 and L58. SEM-EDS analysis showed that， after oleic acid treatment， the percentage content of Cd and iron （Fe） atoms on the root surface of rapeseed variety H38 decreased and the percentage content of carbon （C） atoms increased； the percentage contents of Cd， C， and Fe on the root surface of rapeseed variety L58 decreased. 【Conclusion】 D-leucine and 4-guanidine butyric acid can promote the uptake and accumulation of Cd in rapeseed， while oleic acid and estradiol can inhibit the Cd enrichment of rapeseed. Therefore， they can be developed and utilized as natural activators or passivators of heavy metal Cd in the soil of arable land.