With the increasing of x, the ZFC (zero-field cooling) M - T curves for the polycrystals La0.6-xGdxSr1.4MnO4 (x=0, 0.1, 0.2, 0.4, 0.6) change from spin-glass-like to paramagnetic, and each ZFC M - T curve has an inflection point at 20K. These behaviours can be understood by considering the respective contributions of Mn and Gd to the total magnetism. In addition, for all the samples, thermal activation conducting behaviours are observed from 100 K to room temperature. Due to the strong antiferromagnetic coupling between neighbouring Mn ions, there is no obvious magnetoresistance effect until the magnetic field strength rises to 3.98 × 106A/m.