The effect of grinding on superconductors of Y-123 and Bi(Pb)-2223 phases and phase formation have been studied by means of X- ray diffraction, differential thermal analysis, scanning electron microscope and measurements of the superconductivity. The experimental results show that there is significant difference of grinding effect on Y-123 and Bi(Pb)-2223 phase superconductors. Grinding causes a change of crystalline state to amorphous one for Bi(Pb)-2223 phase superconductor. The effect of the mechanical strain from preparing process and accident on superconductivity of material should be taken into consideration.