La0.67Ca0.33MnO3:mol%Agx (LCMO:Agx, x=0, 0.04, 0.08, 0.10 and 0.20) films were prepared on the single crystalline (100)-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 1T magnetic field, in addition, the metal–insulator transition temperature (Tp) improve 20–26K or 12–18K for the films at a zero or 1T 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:Agx films.