In the present study, we investigated the anticariogenic compounds from Aralia continertalis (A. continnentalis) has been isolated and identified by MS, $^1H-NMR$ and $^{13}C-NMR$. The MeOH extract was suspended in $H_2O$ and sequentially Partitioned with $CHCl_3$, EtOAc, and n-BuOH. The $CHCl_3$ fraction showed remarkable antibacterial activity against S. mutans. The antibacterial activity compounds against 5. mutans by MIC was isolated successively through the screening system and various chromatography methods. From this active chloroform subfraction, isolation and identification finally gave continentalic acid by spectroscopic methods (MS, $^1H-NMR$ and $^{13}C-NMR$) as an active principle. The compound, continentalic acid, showed significant growth, acid production, adhesion and water-insoluble glucan synthesis inhibitory effect against 5. mutars. These results suggest that continentalic acid from A. continentalis may inhibit cariogenic properties of S. mutans and these properties may provide some scientific rationales that the local inhabitants used the extracts for treatment of dental diseases.