Objectives:The purpose of this study was to evaluate the tooth erosion potential of liqueur and to confirm the anti-erosive effect of calcium. Methods: After purchasing commercially available liqueur in Korea and measuring the pH, products with low pH and high consumption were selected and used as experimental beverages. Calcium (1%) was added to the selected beverages. Chamisul was used as a negative control, and Coca Cola was used as a positive control. Healthy bovine teeth samples were soaked in the selected beverages for 1, 3, 5, 10, 15, and 30 minutes. The changes in the tooth surface after beverage treatment were observed and analyzed using microhardness (VHN, Vickers hardness number) and scanning electron microscopy. Results: Jinro Grapefruit (-88.03±13.05) had the highest surface microhardness difference (ΔVHN) before and after 30 minutes of treatment in each group, followed by Coca Cola (-61.31±21.90) (P<0.05), Jinro Grapefruit+Calcium (there was no significant difference (-25.46±4.43)), and Chamisul (-3.53±27.79) (P>0.05). When comparing changes in surface microhardness over time, Jinro Grapefruit+Calcium (pH 3.75) had slightly lower surface microhardness than Chamisul, but the difference was not statistically significant. Jinro Grapefruit+Calcium has a lower surface microhardness change value than Coca-Cola and grapefruit dew group (P<0.05), so it is thought that the risk of tooth erosion is lower than that of the two groups. Conclusions:The study results suggest that the consumption of liqueur with a low pH may increase the risk of tooth decay. Therefore, it is necessary to recognize the risk of tooth decay when ingesting liqueur and seek dietary guidance that can minimize damage. It was also determined that manufacturers need to consider ways to lower the risk of tooth decay, such as adding appropriate amounts of calcium to the beverages.