In recent years a major challenge in biomaterials is to produce porous materials with similar composition to bone tissue. Hydroxyapatite (HA) is characterized by its high biocompatibility and close chemical similarity to biological apatite and has been used as an artificial bone graft material in many clinical trials. Porous HA is more degradable and osteoconductive than bulk Hydroxyapatite. However, the mechanical properties of porous HA are too weak for load bearing applications. Results confirmed that the mechanical, Physical and biological properties of HA porous scaffolds could be modified using the addition of suitable secondary components. CaO-SiO 2- MgO bioceramics demonstrated high bioactivity and good mechanical properties. Bredigite is a Ca, Si and Mg-containing bioceramic. Results showed that Ca-Si-Mg containing bioceramics not only possessed an improved mechanical strength when compared with hydroxyapatite and ceramics, but also were degradable. The aim of this study is to develop three-dimensional HA-bredigite porous scaffolds using space holder technique. HA and bredigite nanopowders were synthesized via sol-gel and combustion sol-gel respectively, and then various ratios of HA and bredigite nanoparticles (5, 10 and 15 wt. % bredigite) were mechanically combined. Then, after addition of poly vinyl alcohol (PVA) and sodium chloride as space holder, they compacted using compression. In order to sinter the compacted powders, remove sodium chloride and PVA powders and develop porous structure, samples were heat treated at 1350 ?cfor 2h. X-ray diffraction (XRD) technique was utilized to confirm presence of the desired phases in the structure and also, to determine the crystallite size and crystallinity of the prepared scaffolds. The crystallite sizes were calculated by Scherrer and modified Scherrer equation and the results were compared. To evaluate the shape and size of the particles and crystallites, A transmission electron microscopy (TEM) was applied and the size of HA nanopowder particles was calculated around 30 nm. Scanning electron microscopy (SEM) was applied in order to study morphology and surface of nanopowders and scaffolds before and after soaking in simulated body fluid (SBF). Energy dispersive X-ray spectroscopy (EDS) was utilized to evaluate the chemical composition and distribution of elements in scaffolds. Furthermore, axial compression test was applied to study the mechanical properties of scaffolds. Bioactivity of different scaffolds was investigated by soaking them in SBF for various periods. The concentration of calcium and phosphorus ions in SBF and the content of pH of SBF were determined for various periods by ICP-OES method and pH meter, respectively. In order to verify the biocompatibility of scaffolds, MTT assay was applied. Results showed that composite scaffolds with pore sizes in the range of 220-310 ?m , appearance porosity of 63-75 (%) and compressive strength of 1-1.7 (MPa) were developed. SEM images of scaffolds after soaking in SBF depicted the tiny agglomerated bone-like apatite particles. Also, biocompatibility evaluations by MTT method showed that scaffolds could stimulate cell proliferation of Osteoblast-like cells and they did not have any cytotoxicity, as compared to control sample. Considering the results obtained, it seems that, manufactured scaffolds could be a good candidate for bone tissue engineering. Keywords : Porous materials, Hydroxyapatite, Bredigite, Mechanical properties, Biocompatibility.