Abstract: To improve hydrogen absorption-desorption performance of TiMn₂ alloy, partially manganesein the alloy was substituted by iron or iron-vanadium. XRD （X-ray diffraction） shows that thesubstitution results in phase constitution transformation from single TiMn_1～2 to two phases coexistenceof TiMn_1～2 and δMnV. P-C-T （pressure-composition -temperature）curves indicated that thehysteresis factor of hydrogen absorption and desorption decreases and hydrogen storage capacityincreases after manganese substituted by vandium. The entropy and anthalpy of hydrogen absorption could be calculated from P-C-T curves at different temperatures. The enthalpy values of TiFe_0.1Mn_1.9 and TiFe_0.1V_0.2Mn_1.7 are -36.9 kJ/molH₂ and -21.19 kJ/molH₂ respectively.