Yunnanopilia longistaminea is a unique flavor forest vegetable that is mainly determined by the vitamins, amino acids and derivatives, and flavonoids detected in its leaves. This experiment applied to broad targeted metabolomics approach based on UPLC-MS/MS to evaluate metabolic changes and the assessment of differential genes by transcriptome sequencing using the IlluminaHiSeq platform between the Y. longistaminea young leaves (YYL) and mature leaves (YML). The present results showed that a total of 488 compounds in the leaves, of which 275 (56.53%) significantly changed metabolites (SCMs). Compared to young leaves, the abundance of 163 SCMs was down-regulated and 112 SCMs were significantly increased in mature leaves. The results show that flavonoids, amino acids and derivatives, coumarins, nucleotides and derivatives, vitamins, saccharides and alcohol, tannin, and organic acids were significantly downregulated in mature leaves, whereas mature leaves had higher lipids and alkaloids than young leaves. A total of 2082 DEGs were identified, with 939 down- regulated genes and 1143 up-regulated genes in mature leaves compared to young leaves. The experimental work presented here provides the first investigations into Y. longistaminea with metabolic group and transcriptome. This study will prove useful in expanding our understanding of how to analyze biosynthesis at the molecular level, which will encourage further utilization of the Y. longistaminea and its relevant forest vegetables.