Objectives: We examined the effect of commercial plum beverages on dental erosion and whether the addition of calcium to these beverages would inhibit dental erosion. Methods: We analyzed three groups as follows: Maesil 1 group (Chorok Maesil), Maesil 2 group (Sunkist plum), both of which were selected from commercially-available plum beverages, and Calcium-added maesil group (addition of 3% calcium to Chorok Maesil). For negative and positive control groups, Jeju Samdasoo and Coca Cola were selected, respectively. The characteristics of the experimental beverages were analyzed, and the specimens were immersed in the experimental beverage. The degree of erosion was measured by Vickers hardness number (VHN) and scanning electron microscope images. Results: Positive control group had the lowest pH (2.50±0.03), followed by Maesil 2 (pH 2.59±0.01), Maesil 1 (pH 2.81±0.02), calcium-added maesil (pH 4.19±0.01), and negative control group (pH 7.57±0.06). Significant differences were found in surface microhardness between positive control, Maesil 1, Maesil 2 and calcium-added maesil group before immersion and at 30 minutes after immersion (P<0.05), and change in VHN (positive control group, ―80.94±20.63; Maesil 1 group, ―69.33±24.88; and Maesil 2 group, ―78.49±18.60 in comparison with negative control group, ―6.57±26.73). There was no significant difference (P<0.05) in change in VHN between calcium-added maesil (―13.02±17.33) and negative control group. Conclusions: Plum beverages can potentially induce dental erosion due to their low pH. However, adding calcium to these beverages can reduce the risk of dental erosion. Therefore, the risk of dental erosion must be considered during consumption of plum beverages, and the addition of calcium into plum beverages may be considered as a way to prevent dental erosion.