Mg76-xTi12Fe8Ni4Bx (x=0, 1, 2, 3, 4) alloys were prepared and the effects of substitution of B for Mg on hydrogen storage performances of the alloys were investigated. In the alloys, Mg2Ni and NiTi are main phases and the amorphous degree increases gradually with amount of B content increasing. Partial substitution of B for Mg can decrease the temperature of hydrogen absorption reaction and hysteresis effectively. On the other hand, substitution of B for Mg increases the hydrogen absorption/desorption plateau pressure and decreases hydrogen absorption capacity and absorption/desorption rate