NiTi shape memory alloy (SMA) has a high recoverable strain up to 8%, similar to that of bone (2%), and has a low elastic modulus down to 48 GPa, close to that of dense (cortical) bone (below 20GPa). Recently, porous NiTi with the cellular structure, similar to those of some natural biomaterials such as bone, has been acknowledged as a promising biomaterial to use as artificial bones. The mechanical properties of porous NiTi SMA can be easily adjusted to match with those of the replaced bones by obtaining different porosity and pore sizes through controlling the process conditions. Moreover, its porous structure can allow body tissues to grow inside and body fluids to be traorted through the interconnected pores, which can accelerate the healing process. In present study, porous Ni-Ti shape memory alloy was fabricated by combustion synthesis method as the best process to find open pores in product as an important characteristic for implants. Two separate mixtures were prepared from elemental Ni and two types of Ti powder (with less than 150 µm and less than 20 µm grain size); one of which includes acid as a lubricant and the other with no acid. Use of acid in milling stage prevents from agglomeration of powders, while the powders milled with no acid will agglomerate. Then both milled mixtures were compressed into mold, and shape memory alloy was produced by self-propagating high-temperature synthesis (SHS) procedure after preheating stage. Various effective parameters such as Ti powder size, milling conditions, the amount of compression, preheating temperature and influence of agglomeration in formation of NiTi phase were investigated. To assess the composition phases in the final product, X-ray diffraction (XRD) analysis was performed. The amount of NiTi phase in the final composition was greatly increased by reducing the Ti powder size. Ni-reach and Ti-reach phases such as Ni 3 Ti, Ni 4 Ti 3 and NiTi 2 were both shown in the product prepared from large size Ti powders, whereas NiTi 2 was the only secondary phase in products with synthesis by small size Ti powders whether milled by acid or not. In addition, the general porosity percentage and the open porosity ratio, the ratio of the open porosity to the general porosity, were measured by the liquid wheighing method according to ISO 2738 standard. It was shown that the general porosity of the final product was 52%, consisting of 66% open porosity, that is sufficient for implants since the porosity of cancellous bone is in the range of 30 to 90 %. Keywords: Ni-Ti Shape Memory Alloy, Nitinol, Porous, Combustion Synthesis