The purpose of the study was to investigate the effect of mouthrinse containing pyroligneous liquor on the oral pathogentic bacterium, Streptococcus mutans (ATCC 10556) and Streptococcus sanguis (ATCC 25175). The anticmicrobia activities were examinated to each bacteria with the same concentration of 3X10⁴cfu/ml for mouthrinse containing pyroligneous liquor. The different concentration with about 100㎕, 50㎕ and 10㎕ of mouthrinse containing pyroligneous liquor showed the significant anticmicrobia activities for the bacterium. Minimum inhibitory concentrations(MIC) by paper disc method for each bacteria, Streptococcus mutans (ATCC 10556) and Streptococcus sanguis (ATCC 25175), were measured the inhibition zone diameter, 0.88cm and 1.25cm, respectively.