Novel calcium ferrites with magnetoplumbite structure were prepared by the ceramic technology. The structure, the morphology and the magnetic properties of the samples were investigated systematically by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating-sample magnetometer (VSM) and B-H hysteresis curve measurements. The experimental results show that the magnetic properties of calcium ferrites with Ca2+-La3+-Co2+ substitution can be significantly improved. The remanence, the magnetic induction coercivity, the intrinsic coercivity and the maximum magnetic energy of calcium ferrites have a significant improvement compared with that of strontium ferrites substituted by La3+-Co2+. In addition, the high residual flux density of the magnet can be still kept even the sintered magnet is thin and small.