The aim of this study was to evaluate the effect of a dentifrice containing nano-carbonate apatite (n-CAp) on the occlusion of dentinal tubules using a pH cycling. Eighty human dentin specimens were divided randomly into the following four groups; the negative control group (G1: 0% n-CAp), experimental group (G2: 20% n-CAp), positive control groups (G3: Sensodyne®, G4: DenShield®). They were applied to a pH cycling model for 12 days. The experimental group containing 20% n-CAp showed an occluding rate of the dentinal tubule of 78% compare with the baseline and showed significantly difference occluding effect among the other groups (p<0.05). The dentifrice containing 20% n-CAp was the most effective in occluding the dentinal tubules.