Abstract: Objective To study the in vitro biocompatibility of novel hydroxyapatite (HA) and AO artificial bone β-tricalcium phosphate (β-TCP) with rhesus bone marrow stromal cells (rBMSCs). Methods The third passage of rBMSCs were cultured with HA and β-TCP respectively, with the cells cultured without the materials as the control. The morphology and proliferation of cells were observed by inverted phase-contrast microscope and scanning electron microscope (SEM). MTT assay was used to semiquantitatively evaluate the cell proliferation. Results The rBMSC cocultured with HA exhibited good growth as observed under inverted phase-contrast microscope, without significant difference from the cells in the control group. Some small particles were seen pealing off from β-TCP, and some of the cells died. Under SEM, rBMSCs showed good adhesion to HA with obvious proliferation, but the ratio of adhesive cells was not as high as that in β-TCP group. MTT assay showed no significant difference in the cell number between HA and the control groups, but the cell number in β-TCP group was notably less than that of control group. Conclusion Novel HA has good biocompatibility with rBMSCs for bone tissue engineering, and AO artificial bone still needs improvement to serve as scaffold material for BMSCs.