The development of low platinum catalysts for automotive fuel cells is a way to solve platinum resource constraints. We successfully prepared Pt-nanoflower supported on carbon black in aqueous solution with the aid of Cetyltrimethyl Ammonium Bromide (CTAB). Those nanoflowers showed uniform particle size distribution with average particle size of 27.0 nm. XRD indicated lattice compression for Pt from as-synthesized Pt/C. 71.6% of Pt existed in the form of elementary substance based on XPS. All those assembly nano structure contributed to remarkable area-specific and mass-specific activities in oxygen reduction reaction. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.