The Pb0.962 5La0.025(Mg1/3Nb2/3)1-zTizO3 (z=028, 029, 030, 031) piezoelectric ceramics were synthesized by two-step pre-sintering process. The morphotropic phase boundary (MPB) of ceramics was found at 0.29 mol and 0.30 mol of PbTiO3. Selecting the chemical composition on both sides of morphotropic phase boundary, and the tetragonal phase Pb(Mg1/3Nb2/3)0.66Ti0.34O3 powder and rhombohedral phase Pb1-1.5xLax(Mg1/3Nb2/3)1-yTiyO3 (x=0.083 3~0.041 7, y=0.206 7~0.273 3) powder rhombohedral phase were prepared, respectively. Two crystal phase powders (rhombohedral phase mole fraction w=0.3, 0.4, 0.5, 0.6) were mixed and pressed into disks. The ceramics with the same chemical composition and different crystal phase proportion of Pb0.962 5La0.025(Mg1/3Nb2/3)0.70Ti0.30O3 were sintered. The effect of crystal phase ratio on the piezoelectric, dielectric, and ferroelectric properties of ceramics were investigated. The results show that the rhombohedral and tetragonal phase ratios of ceramics are pasically the same as the proportion of ingredients. For the sample with w=0.5, the rhombohedral and tetragonal phase ratios of ceramics sintered at 1 250 ℃ is about 0.47, 0.53, respectly. The average grain size is (5.24±0.23) μm. The relative density of ceramics is 96.76%. The piezoelectric constant d33, planner electromechanical coefficient kp, thickness electromechanical coefficient kt, relative permittivity εr, remnant polarization Pr, and field-induced strain S (1 Hz, 3.5 kV/mm) of ceramics are 1 014 pC/N, 0.67, 0.64, 10 955, 24 μC/cm2, and 0.21%, respectively. For the chemical composition near MPB, the rhombohedral and tetragonal phase ratios of ceramics could be tuned artificially via this method.