The process of water splitting by using efficient non-precious-metal catalyst to make the process economically viable has brought forward an extensive research. In this study, the composite of Cu and MoS2 on the reduced graphene oxide (rGO) (Cu-MoS2/rGO) with high catalytic activity toward hydrogen evolution reaction (HER) was easily synthesized using hydrothermal method and chemical process. It was found that the participation of rGO improved the electrical conductivity of the catalyst, and the MoS2 nanoflowers (NFs) with a higher number of exposed edges exhibited higher HER activity. In addition, the addition of Cu particles could not only enhance the electrical conductivity of the catalyst, but also further improved the catalytic activity by synergistic effect with MoS2 NFs. Electrochemical experiments demonstrated that the catalyst exhibited excellent HER activity with large cathode currents and a Tafel slope as small as 90 mV decade(-1). Furthermore, it was discovered that the current density of this composite catalyst had a little decrease after the continual 700 cycling, which showed the catalyst had a high stability in the recycling process. These findings confirmed that this catalyst was a useful and earth-abundant material for water splitting. (C) 2015 Elsevier B.V. All rights reserved.