The major ingredient of Cinnamomum, which is cinnamic aldehyde, has a variety of uses, such as aromatic compound, beverage, chewing gum, toothpaste, and incense as a component of cosmetics, and halitosis remover. Cinnamic aldehyde is also known to have a remedial effect. In this study, Cinnamomum is used to look for antibacterial activity on oral bacteria. A disk diffusion method is used as the current antimicrobial susceptibility test. Accordingly, this study used the disk diffusion method, wherein antibiotics are used to block the growth of bacteria in order to measure the antibacterial activity. As a result of measuring the antibacterial activity of Cinnamomum extract, Gingivalis and bacteria both appeared to have antibacterial activities. The antibacterial effects of Cinnamomum extract were proven by the disk diffusion method. Therefore, it can be suggested that using Cinnamomum verum as a natural remedy is effective on several oral diseases, including dental caries, and can be used as a substitute for other existing chemicals.