Objective To observe the effects of micro-arc oxidation (MAO) and alkali (NaOH) treatment on theporous surface tantalum, and evaluate the biocompatibility and osteogenic ability of porous tantalum in vivo. Methods Porous tantalum was immersed in simulated body fluid (SBF) for 1 week after MAO and alkali treatment. Micropores,calcium, and phosphorus deposition on the surface were observed by scanning electron microscopy (SEM). The contact anglewas observed by X-ray photoelectron spectroscopy (XPS). For in vivo experiments, bone healing was evaluated at 4 and 12weeks after the porous tantalum implantation into a rabbit skull defect model. Results Compared with the control and MAOonlytreated specimens, NaOH-treated tantalum metal formed more apatite on its surface in SBF. Moreover, a sodium tantalatehydrogel layer and reduced contact angle were observed on the specimen surface by XPS ( P < 0. 05). In vivo, the woundshealed well and there was no swelling or suppuration in the rabbit implant model. Computerized tomography imaging revealedthat the porous bract and surrounding bone tissue were well coupled after 4 and 12 weeks. Calcein fluorescent labeling anddetection indicated that new bone had grown into the interior of the multi-porous material at 12 weeks. Moreover,neovascularization and new trabecular bone were observed by SEM. Conclusions MAO and alkali treatment can change the surface shape of porous tantalum material, exhibiting good biocompatibility and osteogenic ability in vivo.