In this paper, the effect of La3+ doping on the structure, charge ordering and magnetic properties of Sm0.5Ca0.5MnO3 manganite has been studied. A series of LaxSm0.5-xCa0.5MnO3 (x = 0, 0.25, 0.375, 0.5) samples are prepared by traditional solid state reaction. The crystal structures are studied by X-ray diffraction technology. The results show that they are single-phase and orthorhombic structures. The change of La3+ ion concentration does not change the crystal structure of the samples. The surface morphology and particle size of the samples are studied by scanning electron microscope. The av...