To investigate the remineralization effect of 38% silver diamine fluoride (SDF) on the artificial incipient carious lesion in primary teeth by analyzing mineral density and remineralization percentage of the lesions. Eighteen sound primary incisors were selected to create artificial carious lesions and scanned using Micro Computed tomography scanner (Micro CT) to determine the baseline mineral density of the initial lesions. The samples were randomly allocated into 2 groups [A: deionized water, B: SDF; n=9]. Nine teeth in group B were applied with SDF, while the other group was the control. After that, all samples in both groups were undergoing in pH-cycling process for 7 days and mineral density was re-evaluated and analyzed. The pre and post-treatment mineral densities were used to calculate the remineralization percentage of both groups. A dependent t-test in parametric statistics was used to compare mineral density between pre and post-test within the SDF group. Wilcoxon Signed Ranks test was used to compare mineral density between the pre and post-test within the control group. The percentages of remineralization of both groups were compared using the Mann-Whitney test. Statistical analysis was performed using SPSS version 20 (SPSS Inc., Chicago, IL, USA) with a significance level set at 0.05. The post-test of mean mineral density in the SDF group was significantly higher than the pre-test. However, there was no significance between the pre and post-mineral density in the control group. Furthermore, the mean percentage of remineralization of SDF was significantly higher than the control group. The reason supported the higher remineralization effect of SDF on incipient carious lesion are the mechanism of action and high concentration of fluoride. The SDF can be effectively used to enhance the remineralization and inhibit the demineralization in initial carious lesions of primary teeth.