Fast capacity degradation is a significant drawback hindering La-Mg-Ni-based alloys from wide application as anode electrode materials of nickel metal hydride batteries. Herein, the effect of Pr element on the phase structure and cycling stability of La0.8-xPrxMg0.2Ni3.4Al0.1 (x = 0, 0.1, 0.2 and 0.3) alloys is investigated. All the alloys contain (La, Mg)(2)Ni-7 and (La, Mg)(5)Ni-19 main phases as well as LaNi5 minor phase. It is found that Pr tends to form [AB(5)] subunits more than [A(2)B(4)] subunits, thus increasing the content of (La, Mg)(5)Ni-19 phase with higher [AB(5)]/[A(2)B(4)] ratio in sacrifice of (La, Mg)(2)Ni-7 phase. The increased (La, Mg)(5)Ni-19 phase network with good structural stability increases the anti-pulverization and anti-amorphization resistance of the alloys. After 100 charge/discharge cycles, part of the superlattice phases in La0.6Mg0.2Ni3.4Al0.1 alloy decomposes into amorphous phase and LaNi5 phase, leading to the decrease in superlattce phase abundance; while little amorphization is observed for La0.6Pr0.2Mg0.2Ni3.4Al0.1 alloy and its phase contents remain almost unchanged. Correspondingly La0.6Pr0.2Mg0.2Ni3.4Al0.1 alloy electrode has a slighter oxidation degree after 100 cycles in alkaline electrolyte and exhibits good electrochemical cycling stability with a discharge capacity of 340 mAh g(-1) and a cycling stability of 90.7% at the 100th cycle. (C) 2015 Elsevier Ltd. All rights reserved.