Abstract: Saliva buffer act as an important factor to control the pH of the mouth environment. Because organic acids produced by the mouth microorganisms is associated with development of dental caries, the aim of this study was to compare the buffering capacity of saliva in active dental caries patients with caries free subjects. Saliva samples were collected without stimulation from 30 patients with more than 10 decayed teeth and 30 subjects with no dental caries. The pH of saliva was measured and the buffering capacity of each saliva sample was determined by either HCl (1:10 N) or NaOH (1:10 N) titration. The determination of pH values of patients with active caries and caries free subjects were 6.67 ± 0.03 and 6.76 ± 0.03, respectively which are not significantly different. However, the pattern of titration of the saliva in the patients was different from that of titration of the healthy subject. The differences were significant particularly after addition of 1-3 mL of either HCl or NaOH solution. The result suggested that the determination of the buffering capacity of the saliva may be used as an index for the development of dental caries.