The biomedical porous NiTi alloy was prepared by atmosphere sintering process, and the effects of NH4HCO3 contents on the microstructure, bending strength, elastic modulus and corrosion resistance of the biomedical porous NiTi alloy were investigated. The results show that with increasing the NH4HCO3 content, the porosity and pore size of the porous NiTi alloy increase, while the bending strength, elastic modulus and corrosion resistance all decrease. The porosity of the porous NiTi alloy is about 36%~62%, the pore size 50~300 μm, the bending strength about 22~220 MPa and the elastic modulus about 0.7~6 GPa. All of these parameters are very close to that of human bones, indicating that these porous NiTi alloys could be used as the candidate of human hard tissue replacement materials