Introduction: : Allium sativum L which is well known as garlic has been reported to be a potential source of antiox-idants. Potential sources of natural antioxidants one of them are garlic. The use of garlic as a drug has often been usedoffers numerous advantages in treating various diseases including those caused by bacterial infections such asin dental caries and oral diseases. Black garlic is a processed product of garlic which is heated at a temperature of 60-80oC with high humidity for 1-3 months. The objective of this study was to clarify antioxidant test of black gar-lic extract with 96% ethanol and sterile distilled water solvent, growth inhibition test of Streptococcus mutans and Actinomyces naeslundii. Methods: The study used three different black garlic samples to extract with 96% ethanol and sterile distilled water solvent to measure antioxidant test and growth inhibition test of Streptococcus mutans and Actinomyces naeslundii with a concentration of 25%, 50%, 75% and 100%. Results: Three black garlic samples had different antioxidant (IC50) values and the best antioxidants were extract black garlic super® with ethanol 96% solvent. Black garlic extract for inhibiting growth of Streptococcus mutans has a no significant differences (p> 0.05) at concentrations of 100%, 75%, 50%, and 25%, but there were significant differences (p <0.05) in positive control with chlorhexidine 0.2% and negative control with sterile aquadest solvent and for inhibiting growth of Actinomyces naeslundii has no impact. Conclusion: The results of antioxidant test showed that black garlic has a high antioxidant substance but has a weak impact in growth inhibiting of the Streptococcus mutans and Actinomyces naeslundii bacteria.