Abstract: Using the porous Ti-51%Ni (atom fraction) alloy with the porosities of 43%-58% as the research object, the micromorphology, phase composition, phase transformation behavior, and the compression and recovery properties under different compressive loads of the alloy were investigated. And the deformation mechanism was analyzed. The results show that the pores in the tested alloy distributed homogeneously. The porosity had little influence on the phase composition and phase transformation behavior. Two deformation mechanisms, namely the linear superelasticity and the saw-tooth plateau, were found under different compressive loads. At the stage of linear superelasticity, the tested alloy had relatively high compressibility and high recovery rate while almost lost the recovery ability at the stage of saw-tooth plateau.