BACKGROUND:: The hydroxyapatite nanocrystals surface-grafted with L-lactic acid oligomer/poly (lactide-co-glycolde) (PLGA/g-HA) composite material is preferable to good stability and favorable mechanical property. As scaffold cultured with bone marrow mesenchymal stem cells (BMSCs). OBJECTIVE:: To study the bioactivity and biocompatibility of BMSCs cultured with PLGA/g-HA composite material in vitro. METHODS:: Third passage BMSCs of rabbits were cultured in PLGA/g-HA extract at different concentrations (10%, 30%, 50% and 80%), and cell proliferation was detected by MTT method. Meanwhile, the cell adhesion and morphology were observed with scanning electron microscopy. RESULTS AND CONCLUSION:: There was no significant difference between 10% group and negative group at 1 and 3 days after culture. The cytotoxic grade was Grade 1 in all the four concentrations. BMSCs could stretch pseudopodium gradually and adherent on the surface of PLGA/g-HA firmly. The results indicated that: ©BMSCs could proliferate in PLGA/g-HA leaching liquor. ©BMSCs have a good state on the surface of PLGA/g-HA. And we can apply the scaffold to bone defect repair, because of its good biocompatibility and cellular adhesion.