In this study, TEOS - CaCl2 and Mixed TEOS-MAPTMS-CaCl2 were synthesized via sol-gel method and evaluated as a bioactive bone substitute. The hydrolysis and condensation were achieved in an (ethanol/water) solution. The ratio of silane to water to ethanol was 1:3:3. Bioactivity of the samples was premeditated via in-vitro test by inundation in simulated body fluid (SBF) to assess the creation of a hydroxyl apatite (HA) layer on the surface of the samples. Structural characterization of the prepared samples was done using Thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and fourier transform infrared (FTIR) spectroscopy. Elemental Analysis was performed using a UV-Vis Spectrophotometer. Results showed the creation of a layer of hydroxyl apatite (HA) on the surface of the samples. It was found that, sample contain hydrocarbon chain (sample doped with MAPTMS) need higher temperature to lose water and ethanol, i.e. organic precursor increases the thermal stability of the samples. In addition a layer of HA were deposited on the surfaces of the two samples after soaking in SBF for 33 days.