A new catalyst based on Co-P-Se compound that is comprised entirely of cheap and earthabundant elements, was first reported for electrolytic hydrogen production. The hydrothermal method at only 473 K was employed to prepare the nanoparticles (NPs) of Co-P-Se compound. The transmission electron microscope images reveal the nanoparticles of quasis-spherical structure and extremely small size with an average diameter of around 5 nm. The composites of Co-P-Se NPs and multi-walled carbon nanotubes (MWCNT) was loaded onto the electrode surface as an active hydrogen evolution reaction (HER) electrocatalyst, which is observed using a scanning electron microscopy. The electrochemical study shows that MWCNT helps to load more Co-P-Se catalysts and enhance the electron transfer between catalysts and electrode, and Co-P-Se exhibits more catalytic activity than Co-P or Co-Se alone. A small Tafel slope of 46 mV/dec and good acid stability was observed for the hydrogen evolution reaction of CoP-Se/MWCNT. (C) 2015 Elsevier Ltd. All rights reserved.