Terpenes (terpenoids or isoprenoids) play a key role in primary and secondary metabolism in a variety of organisms. In plants, its biosynthesis is catalyzed by two key pathways mevalonate and non-mevalonate pathways. The genome of garden sage plant (Salvia officinalis) contains 65 terpene synthase (SoTPS) genes, and only a few genes which related to terpenoids were studied. Here, we demonstrate the functional characterization of beta-amyrin synthase (SoAMYS) gene, by introducing it into Arabidopsis thaliana and found that SoAMYS overexpression improved the flowers formation in transgenic Arabidopsis compared to the wild type plants. Metabolic analysis reported that the production of various types of terpenes, especially beta-amyrin triterpene which, were increased and decreased in SoAMYS overexpression and wild type lines, respectively. These finding suggesting that SoAMYS functions as a beta-amyrin synthase in plant. Our results were further supported using some bioinformatics tools to predict the putative subcellular localization and tissue-specific expression of SoAMYS. In context that, SoAMYS gene was reported to be localized in plastids with highly expression level in flowers stage 15, pedicels. This is the first report of a gene involved in the beta-amyrin as a triterpene from S. officinalis plant.