The alloys were prepared by a non-consumable vacuum arc melting and homogenized at $1050^{circ}C$ for 24 hrs. Two kind of surface modifications were performed alkali treatment in 5.0M NaOH solution subsequent and heat treatment in vacuum furnace at $600^{circ}C$, and were oxidizing treatment at the temperature range of 550 to $750^{circ}C$ for 30 minutes. After surface modification, these samples were soaked in SBF which consists of nearly the same ion concentration as human blood plasma. Cytotoxicity tests were performed in MTT assay treated L929 fibroblast cell culture, using indirect methods. A porous and thin activated layer was formed on Titanium and Ti-8Ta-3Nb alloy by the alkali treatment. A bone-like hydroxyapatite was nucleated on the activated porous surfaces during the in vitro test. However, Ti-8Ta-3Nb alloys showed better bioactive properties than Titanium. According to XRD results, oxide layers composed of mostly $TiO_2$(rutile) phases. Cytotoxicity test also revealed that moderate oxidation treatment lowers cell toxicity and Ti-8Ta-3Nb alloy showed better results compared with Titanium.