The composition of hydrogen storage alloy particles used in a negative plate of an alkaline secondary battery is expressed by a general formula: (La.sub.a Pr.sub.b Nd.sub.c Z.sub.d).sub.1-w Mg.sub.w Ni.sub.z-x-y Al.sub.x T.sub.y. In the formula, Z is an element selected from the group consisting of Ce and others, and T is an element selected from the group consisting of V and others. Subscripts a, b, c and d fall in ranges of 0.ltoreq.a.ltoreq.0.25, 0