<p>There is a lack of systematic analysis and research on the special components of red beet and sugar beet, which are common beet varieties rich in a variety of beneficial chemicals. To investigate the differences in the composition of flavonoids and terpenoids in roots of red beet and sugar beet, poinsettia(red beet) and HD802(sugar beet) were detected and analysed in the present study by using the UPLC-MS/MS detection platform and the MWDB(Metware database), and orthogonal partial least squares discriminant analysis (OPLS-DA) was used to screen out the differential metabolites from the detected flavonoid metabolites and terpenoids metabolites. A total of 69 flavonoid metabolites from 6 classes and 48 terpenoids from 6 classes were detected in two kinds of beet roots. Analysis of variance (ANOVA) showed that the content of 5 flavonoid and 4 terpenoid differential metabolites was higher in red beet roots than in sugar beet roots, and the content of the remaining 25 flavonoid and 2 terpenoid differential metabolites was lower than that of sugar beet roots. According to the metabolite Log₂FC, the components of the flavonoid metabolites with large difference ratio were mainly Polymethyl flavonoid derivatives, Iso-rhamnoside and Rhamnoside, Marigold glycoside, Methoxyl flavonoid derivatives, Diosmetin derivatives, Chrysoeriol and its derivatives, Luteolin derivatives, Homonetsin derivatives and Kaempferol derivatives. Significant differences in flavonoid metabolites and terpenoid metabolites between the two beet roots were found by non-targeted analysis of variance and can be further analysed as characteristic metabolites.</p>