Abstract: The aim of this study is to investigate anti-bacterial activity and cytotoxicity of Aster sphathulifolius Maxim. (A. sphathulifolius) against oral pathogens and oral carcinoma cell lines. For the private hygiene, the health of mouths is very important for maintaining entire body healthy. Some chemical agents, used in products for health of mouths, are reported to have bad side-effects. Therefore there is a growing interest in safe and natural materials with pharmaceutical activity. Anti-bacterial activity of A. sphathulifolius extract was performed using agar-diffusion assay against several oral pathogens and anti-carcinogenic activity was carried out by cell viability assay for oral cancer cell lines. Whole plant-extract of A. sphathulifolius showed the anti-bacterial activities against all tested oral pathogens except of Staphylococcus aureus (S. aureus). Anti-bacterial activities against Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus), Streptococcus pyogenes (S. pyogenes) and Staphylococcus epidermidis (S. epidermidis) were observed by most of all parts of A. sphathulifolius. However, the growth of S. aureus was inhibited by only root-extract of A. sphathulifolius., A. sphathulifolius showed the outstanding cytotoxicity against human oral gingival carcinoma cells with approximately 75.1 and 93.1% cell death in 250 and 500 μg mL-1 of concentrations, respectively. A. sphathulifolius extracts had the anti-bacteria activity against oral pathogens and the cytotoxicity of oral carcinoma cell lines together. Taken together, it is anticipated that A. sphathulifolius might be used for the oral health care, as mouthwashes and toothpastes form with an alternative therapeutic drug.