This study was to evaluate the effect of bleaching teeth with whitening toothpaste on tooth whitening and mineral contents. We randomly assigned 40 human anterior teeth to two groups as follows (n=20): general toothpaste was used in Group 1 as control and whitening toothpaste was used 3 times a day for 3 min in Group 2. The total study period of the enamel specimens in each group was measured for 8 weeks at 2-week intervals. After each application, teeth were washed distilled water and subsequently immersed in artificial saliva. The color changes of the teeth were numerically characterized based on the Commission Internationale de L’Eclairage (CIE) Lab Color system. The main mineral contents of the enamel surface were analysed the field emission electron probe micro analyser (FE-EPMA: electromagnetic wave). The data were analysed using Student t-test with SPSS 20.0 statistical computer program (SPSS Inc., USA). The overall color changes (ΔE) were 6.18 ± 1.15 in Group 1 and 13.41 ± 1.86 in Group 2; the ΔE values were significantly different after 8 weeks of application (p<0.05). The whitening toothpaste improved the whitening efficacy of the enamel by a factor of 2.2-fold compared to that by the control toothpaste. Further, the mineral content did not appear to differ between the groups (p>0.05). Whitening toothpaste provided effective tooth whitening, and the efficacy increased in a timedependent manner. Moreover, the application of whitening toothpaste did not have a deleterious effect on the enamel.