Pt-based nanocrystals with controlled morphologies and structures are one of most promising electro-catalysts for oxygen reduction reaction (ORR). Herein, a facile one-pot wet-chemical method is developed to synthesize Pd@PtNi core-shell nanoflowers (CSNFs) supported on the multi-walled carbon nanotubes (MWNCTs). Brij 58 is demonstrated as a structure-directing agent to generate the nanoflower and ascorbic acid acts as a reductant to form a core-shell structure. By tuning the molar ratio of Pd and Pt, Pd@PtNi/MWCNTs CSNFs show obviously improved ORR activity and durability in alkaline electrolyte compared with PtNi/MWCNTs nanoflowers and commercial Pt/C. The results illustrate that the core-shell structure and porous feature of nanoflower are both beneficial to the enhancement of the catalytic properties. (C) 2017 Elsevier B.V. All rights reserved.