La0.67Ca0.33MnO3:mol%Ag-x (LCMO:Ag-x, x = 0, 0.04, 0.08, 0.10 and 0.20) films were prepared on the single crystalline (1 0 0)-orientated (LaAlO3)(0.3)-(SrAlTaO6)(0.7) (LSAT) substrates by the pulsed laser deposition (PLD) method. With the increasing of Ag addition, the magnetoresistance (MR) of the LCMO:Agx films exhibits a significant decrease and the x = 0 sample reach to the maximum value of MR ratio at 46.6% under IT magnetic field, in addition, the metal-insulator transition temperature (T-p) improve 20-26K or 12-18K for the films at a zero or 1 T fields, respectively. The results maybe due to the fact that Ag enter the host lattice, partially substitute for La3+/Ca2+ ion, and then increase the Mn4+/Mn3+ ratio, which lead to enhance the electrical properties in LCMO:Ag-x films. (C) 2015 Elsevier B.V. All rights reserved.