Present work is dedicated to the investigation of grain boundary (GB) wetting phase transition on different types of grain boundaries in the Cu–Ag system. The character of GBs in the samples was determined by the electron backscattering diffraction. GB character distribution was based on the coincidence site lattice (CSL) model and on the values of the misorientation angle of GBs. Experimental results show that only the low angle GBs and the Σ3 CSL GBs do not reach complete wetting by the melt. Random high misorientation angle (HA) GBs reach complete wetting at 895 °C. Only Σ11, Σ5 and Σ13 CSL GBs have a higher wetting temperature than the HA GBs, so their GB energy should be lower than the energy of HA GBs.