Silicon (Si) incorporated porous TiO 2 coating (Si-TiO 2) prepared on titanium (Ti) by micro-arc oxidation (MAO) technique was demonstrated to be cytocompatible in previous studies.In view of the potential clinical applications,a detailed in vitro study of the biological activity of Si-TiO 2 coating,in terms of osteoblast (MC3T3-E1 cells) morphology,proliferation,differentiation and mineralization was performed.Immunofluorescent staining indicated that cells seeded on the Si-TiO 2 coating showed improved adhesion with developing mature cytoskeletons,which contained numerous distinct and well-defined actin stress fibers in the cell membranes compared with those on the TiO 2 coating and Ti plate.Results from proliferation assay showed that the proliferation rate of cells seeded on the Si-TiO 2 coating was significantly faster than that on the TiO 2 coating and Ti plate.Furthermore,the analysis of osteogenic gene expression demonstrated that the Si-TiO 2 coating stimulated the expression of osteoblast-related genes and promoted differentiation and mineralization of MC3T3-E1 cells.In addition,the Si-TiO 2 coating differentially regulated Wnt signaling pathway by up-regulating the expression of low-density lipoprotein (LDL) receptor-related protein 5 (Lrp5),and downregulating the expression of Dickkopf-1 (Dkk1).All together,these results indicate that the investigated titanium with Si-TiO 2 coating is biocompatible and a good candidate material used as implants. Silicon (Si) incorporated porous TiO 2 coating (Si-TiO 2) prepared on titanium (Ti) by micro-arc oxidation (MAO) technique was demonstrated to be cytocompatible in previous studies. In view of the potential clinical applications, a detailed in vitro study of the biological activity of Si-TiO 2 coating, in terms of osteoblast (MC3T3-E1 cells) morphology, proliferation, differentiation and mineralization was performed. Immunofluorescent staining indicated that cells seeded on the Si-TiO 2 coating showed improved adhesion with developing mature cytoskeletons, which contain numerous distinct and well-defined actin stress fibers in the cell membranes compared with those on the TiO 2 coating and Ti plate. Results from proliferation assay showed that the proliferation rate of cells seeded on the Si-TiO 2 coating was significantly faster than that on the TiO 2 coating and Ti plate. Future, the analysis of osteogenic gene expression demonstrated that the the Si-TiO 2 coating stimulated the expression of osteoblast-related genes and promoted differentiation and mineralization of MC3T3-E1 cells. In addition, the Si-TiO2 coating differentially regulated Wnt signaling pathway by up-regulating the expression of low-density lipoprotein (LDL) receptor- Lrp5), and downregulating the expression of Dickkopf-1 (Dkk1) .All together, these results indicate that the investigated titanium with Si-TiO 2 coating is biocompatible and a good candidate material used as implants.