Objectives: The aim of this study was to evaluate the remineralization effect on artificial caries-like lesions by combined nano-sized carbonate apatite (n-CAP) and fluoride compounds such as sodium fluoride (NaF) or sodium monofluorophosphate (SMFP). Methods: The bovine specimens formed artificial caries lesion were assigned to one of the following groups (n=12): silica 10% dentifrice (control); 1000 ppm NaF dentifrice; 1000 ppm SMFP dentifrice; 1000 ppm NaF with 5% n-CAP dentifrice; 1000 ppm SMFP with 5% n-CAP dentifrice. The pH-cycling was processed for 14 days. The toothpaste slurries were prepared by mixing 6.7 g of the dentifrice in 13.3 ㎖ of deionized water. In the case of combined n-CAP and fluoride compounds, two components were mixed immediately before treating the specimens. After demineralizing and pH-cycling, the enamel VHN and SEM was again measured. The differences between the baseline or after the treatments (ΔVHN) were evaluated by ANOVA and a Tukey`s test (a=0.05) for all variables. The analyses were carried out using the SPSS System 12.0 software. Results: After 14 days of the pH cycling procedure, NaF group had the highest VHN value (150.23±25.52, p<0.05). NaF and SMFP groups combined with n-CAP were less remineralized than NaF-only and SMFP-only groups, respectively. The two groups combined with n-CAP and fluoride groups showed the much higher coverage of calcium fluoride globules than those of only fluoride compounds groups. Conclusion: The combination of n-CAP and fluoride compounds did not show any synergistic increasing effect of surface microhardness. However, we could find out significant increasing effect of calcium fluoride deposition on the surface.