The hydrogen storage properties of LaNixMn0.26Aly alloys were investigated. Results show that when y=0.13, the lattice parameters (a and c) and the lattice volume V are increased, the absorption plateau pressure is slightly decreased, the desorption plateau pressure is almost the same and the hysteresis factor is improved, while the hydrogen intake capacity is impaired, and the stability of metal hydride is enhanced with decrease of the x. As for LaNi4.4Mn0.26Al0.34 alloy, the lattice parameters and cell volumes are increased, the absorption/desorption plateau pressure is obviously decreased, the hysteresis factor and the absorption kinetics are greatly improved, while the hydrogen content is obviously impaired with Al substituting for partial Ni