In this study, graphene (GP) supported Co-Sn-B alloy were synthesized via in situ chemical reduction reactions for hydrogen generation (HG) from alkaline sodium borohydride (NaBH4). X-ray diffraction (XRD), high resolution transmission electron Microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) were employed to verify the structure, morphology and the surface element composition of the alloy. Coupled plasma atomic emission spectrometry (ICP-AES) were used to analyze the surface composition of the alloy. The effects of complexing agent addition, Co/Sn molar ratio, graphene loading on catalytic activity of the alloy were studied. The maximum hydrogen generation rate reached 11,272 mL min(-1) g(Co)(-1) at 30 degrees C in 5 wt. % NaOH and 5 wt. % NaBH4 solution, which was three times higher than unsupported Co-B catalysts. The activation energy of the catalytic hydrolysis reaction of sodium borohydride was 39.57 kJ/mol, which is comparable to the noble metal catalysts. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.