In order to explore relevant information of flavonoid componts and their synthases in Portulaca oleracea L., we utilized both the transcriptome and metabolome to analyze the root, stem and leaf of P. oleracea L. At the same time, 6 differential expressed genes were identified by the RTPCR. The results showed that: (1) by the metabolome, there were 32 flavonoid components included 3 isoflavones, 8 flavonols, 11 flavones, 3 flavanones, 5 flavanols and 2 canthocyanidins in which the contents of 20 flavonoid components were similar, while the other 12 ones were significantly different in root, stem and leaf of P. oleracea L. (2) By the transcriptome, there were 93 flavonoid synthases which included 20 CHSs, 3 CHIs, 7 F3Hs, 2 ANSs, 11 IFSs, 21 F3′Hs, 2 F3′5′Hs, 2 DFRs, 2 ANRs, 1 LAR and 22 UF3GTs in root, stem and leaf of P. oleracea L. (3) According to the result of transcriptome, the expressed trend of these 6 flavonoid synthases agreed with the testing by the RTPCR. However, the trend multiples of these differentially expressed genes by these 2 kinds of approaches were different. So this study concluded that there are many flavonoid components and their synthases in P. oleracea L. including root, stem and leaf, but the contents of flavonoids and the expression of their enzymes in different tissues are distinct.