The La0.67Pb0.33MnO3 (LPMO) thin films doped with Ag on vicinal-cut LaAlO3 substrates were prepared using standard pulsed laser deposition technique, in which laser induced thermoelectric voltage (LITV) effect was found. With Ag doping level x (x is defined as,x=massAg/massLPMO) increasing from 0.00 to 0.10, the response time of LITV signals in LPMO thin films firstly decreases (reaching minimum at 0.06), and then increases (still less than that with zero Ag doping). Further, an optimal film thickness was found, at which the peak voltage and response time of LITV signals to reaches maximum and minimum, respectively. The response time of LITV in the LPMO thin films are substantially smaller than that of La0.67Ca0.33MnO3 thin films at the same Ag doping level.