The bioactivity of a composite of titania and hydroxyapatite was studied in vitro in this paper. After the titania ceramics was added 10% HA, it could induce apatite formation in simulated body fluid in 2d, while the pure titania ceramics could not induced apatite formation even after 14d. After the composite of titania and HA was subjected to alkali-heat treatment, it has a faster speed for apatite formation in SBF than the composite without treatment. When the osteoblast was cultured on the materials, the amount of osteoblasts attaching on the composite was more than that on the pure titania ceramics. It has the most osteoblasts cells on the composite subjected to alkali-heat treatment. These results showed that the composite of titania and HA is a bioactive materials, while the alkali-heat treatment could improved the bioactivity of this composite.