Much effort has been made to develop cost-effective electrocatalysts for last decades to replace expensive and earth-rare platinum catalysts in hydrogen evolution reaction (HER). Copper sulfide (CuS) has been little used for an electrocatalyst but can have potential as a component of hybrid electrocatalysts. In this study, we demonstrate colloidal syntheses of CuS and its hybrid materials for HER catalysts. The colloidal CuS nanoplatelets showed poor electrocatalytic activity in HER (-526 mV for onset potential and 100 mV/dec for Tafel slope). The low HER performance can be attributed to proton-inaccessibility by hydrophobic ligand, and coverage of active sites by aggregation of nanocrystals. To improve the HER catalytic activity, CuS based hybrid materials with molybdenum disulfide (MoS₂) were synthesized. CuS/MoS₂ hybrid was synthesized by ligand exchange and annealing procedures. Ammonium tetrathiomolybdate ((NH₄)₂MoS₄) was used as a precursor for the ligand exchange. (NH₄)₂MoS₄ was dissolved in N,N-dimethylformamide (DMF) and acted as an inorganic ligand (MoS₄^2-). Simple sonication of a mixture solution consisting of CuS in hexane and (NH4)2MoS4 in DMF exchanged oleylamine ligand of CuS with (MoS₄^2-) to give CuS@MoS_x. During the ligand exchange, stacked CuS nanoplatelets were disassembled by sonication. The HER activity of CuS@MoS_x was improved: -182 mV for onset potential and 88.2 mV/dec for Tafel slope. The improvement would be due to exposure of more active sites by disassembly of nanoplatelets and enhanced proton accessibility by removing oleylamine ligands attached to CuS.