Objective: To observe the effect of calcium on biological characteristics (proliferation, apoptosis and cell cycle) of ALC ameloblasts. . Methods: ALC cell lines were cultured in vitro in DMEM medium with high glucose at different concentrations (0, 2.0, 2.5, 3.0 and 3.5 mmol/L CaCl2 aqueous solution) for 24 h and 48 h, respectively. Changes of ALC cells under two kinds of incubation time were observed with an inverted microscope. CCK-8 method was used to analyze the effect of calcium ion on ALC cell proliferation. Hoechst staining was used to observe the effect of calcium ion on ALC cell apoptosis. PI staining and FCM method were used to analyze the effect of calcium ions on the growth cycle of ALC cells. Western blot was used to detect the effect of calcium ions on the expression of Cyclin A, Cyclin B and Cyclin D in ALC cells Results: In the 0 mmol/L CaCl2 group, ALC cells were oval or polygonal in shape, and the cells were closely connected and grew like paving stones. In other concentration groups, the morphology of ALC cells did not change significantly after calcium intervention for 24 h and 48 h. Results of CCK-8 method showed that the survival rate of ALC cells slightly decreased with increasing calcium ions concentration after calcium intervention for 24 h and 48 h. However, there was no significant differences in this trend. Results of Hoechst staining showed that the number of ALC cell apoptosis did not increase significantly after different concentrations of calcium intervention for 24 h and 48 h. With the increase of calcium ion concentration, results of PI staining and FCM method showed that the cell cycle of ALC cells gradually increased in S phase and decreased in G1 and G2 phase gradually. Western blot results showed that the expression of Cyclin A and Cyclin B in ALC cells decreased and the expression of Cyclin D increased after different concentrations of calcium intervention for 24 h and 48 h. Conclusion In this study, calcium has no significant effect on the proliferation and apoptosis of ALC cells. Calcium, however, has an effect on the ALC cell cycle. Results of this study show that calcium ions has no obvious toxic or side effects on the ameloblasts, which could be used to explore the possible mechanism and effect of calcium on dental fluorosis.