Molybdenum disulfide (MoS2) and its composites are the promising electrocatalysts for the hydrogen evolution reaction (HER) in acidic solution because it is earth-abundant and low-cost. Here we reported the ultrathin molybdenum disulfide nanosheet-coated acetylene black (AB) coated (MoS2@AB) as the electrocatalysts for the HER. The catalysts were synthesized in a facile one-pot solvothermal route. The as-prepared catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM, X-Ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results show that the MoS2 nanosheets on AB have a few layers and many surface Molybdenum defects, which are benefical to the HER catalysis. Electrochemical tests revealed that the existence of AB can't only make the catalyst expose a considerable amount of active sites but also increase the turnover frequency (TOF) value per site. In addition, the MoS(2)COAB(75) Catalyst had excellent electro-catalytic HER performances with a low onset potential (-110 mV), a small Tafel slope (50-60 mV per decade) and the longtime stability (10 h). (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.