The in vitro attachment, spread, and proliferation behavior of osteoblast cells on the plasma-sprayed composite coating with 70wt% zirconia and 30wt% dicalcium silicate were studied. The composite coating shows good cytocompatibility. The human osteoblast cells attached, spread and proliferate well on the surface. The cytocompatibility of the coating was attributed to the incongruent dissolution of dicalcium silicate and the large amount of Si-OH functional groups produced on the surface. The released calcium and silicon ions are also positive to the proliferation of cells. All our results show that the composite coating possesses good cytocompatibility.