Co-free AB5-type LaxMm1-x(NiMnSiAlFe)4.9 (x = 0, 0.45, 0.75, 1) hydrogen storage alloys were prepared by casting and rapid quenching. The phase structures and microstructures of the as-cast and quenched alloys were analyzed and observed by XRD and SEM. The electrochemical performances of the as-cast and quenched alloys were measured. The effects of La content and quenching rate on the microstructures and electrochemical properties of the alloys were investigated comprehensivel y. The obtained results indicate that the Co-free AB5-type hydrogen storage alloy with excellent synthetical electrochemical performances can be prepared by adjusting La content and employing appropriate rapid quenching technique.