The effects of Ce on the proliferation, osteogenic differentiation and mineralization function of a murine preosteoblast cell line MC3T3-E1 in vitro were investigated at cell and molecular levels. The results showed that Ce promoted the proliferation, osteogenic differentiation and mineralization function of MC3T3-E1 cells at concentrations of 0.0001, 0.001, 0.01, 0.1 and 1 μM, but turned to inhibit the proliferation, osteogenic differentiation and mineralization function at concentrations of 10, 100 and 1000 μM. Ce displayed the up-regulation of Runx2, BMP2, ALP, BSP, Col I and OCN genes at concentrations of 0.0001 and 0.1 μM; these genes were down-regulated in the MC3T3-E1 cells treated with 1000 μM Ce. The expression of BMP2, Runx2 and OCN proteins was promoted by Ce at concentrations of 0.0001 and 0.1 μM, but these proteins were down-regulated after 1000 μM Ce treatment. The results suggest that Ce likely up-regulates or down-regulates the expression of Runx2, which subsequently up- or down-regulates OB marker genes Col I and BMP2 at early stages and ALP and OCN at later stages of differentiation, thus causing to promote or inhibit the proliferation, osteogenic differentiation and mineralization function of MC3T3-E1 cells.