An typical giant magnetoresistive (GMR) sample viz. La0.7Pb 0.3MnO3 has been irradiated by 50 MeVLi3+ ion beam. Irradiated samples have been studied from the measurement of resistivity down to 77 K in presence of 1.5 T magnetic field. Although magnetoresistance is not maximum at Tim as the samples are polycrystalline, however, a small peak like structure has been found around Tim. The peak is most prominent for maximum fluence. © 2003 Elsevier Ltd. All rights reserved.