This　paper　reports　a　novel　coprecipitation　process　for　the　preparation　of　strontium-barium　hydroxyapatite　[Sr5-xBax(PO4)(3)OH].　Strontium　nitrate,　barium　nitrate　and　phosphoric　acid　were　dissolved　in　water　to　form　a　homogeneous　Sr-Ba-P　aqueous　solution.　The　samples　were　characterized　by　powder　X　ray　diffraction,　Fourier　transformed　infrared　spectroscopy　and　scanning　electron　microscopy.　The　results　showed　that　the　barium　phosphate　[Ba-3(PO4)(2)]　phase　appeared　at　the　samples　prepared　at　the　pH　value　lower　than　12.　A　series　of　Sr5-xBax(PO4)(3)OH　samples　had　beenobtained　by　adding　sodium　hydroxide　aqueous　solution　into　the　Sr-Ba-P　solution　to　pH12.5　and　following　aging　at　60　degrees　C　for　24h.　The　so-prepared　samples　are　metallic　cation-deficient　hydroxyapatite　solid　solutions.　The　samples　present　low　degree　of　crystallinity,　irregular　short　rod-like　morphology　and　nanometer　size.　The　crystal　cell　parameters　of　Ca5-xSrx(PO4)(3)OH　samples　are　nearly　linear　to　their　barium　content,　and　their　infrared　absorption　bands　of　PO43-　groups　shift　to　lower　wave　numbers　with　the　increase　of　the　barium　content.