Among several techniques proposed for fixing titanium bone implant in bone tissues by inducing apatite deposition on the implant surface, "GRAPE® Technology" is the simplest one, where optimum size of macro-grooving and heating in air are provided for pure titanium because samples with such grooves deposit apatite when soaked in an aqueous solution mimicking human blood plasma. The technique is needed to be confirmed by in vivo tests if it is effective for bone tissues, or if it is applicable to newly developed titanium alloy systems. In this study, the validity of GRAPE® Technology for a Ti-15Zr-4Ta-4Nb alloy was assessed with both in vitro and in vivo experiments. Here, alloy pieces with macro-grooves 500 μm in depth and 500 μm in width were heated at 500°C to induce thin titania layers on the surface. In vivo tests confirmed bone-ingrowth within 3 weeks in the samples with the macro-grooves but very less for those without the grooves. Those results indicated that GRAPE® Technology is effective for providing the Ti-15Zr-4Ta-4Nb-based implants with osteoconductivity.