This thesis consists of two parts: In the first part, The effect of calcination temperature and different type of materials (nitrates and oxcides) on the properties of Bi-2223 superconductors, have been investigated and in the second part, Substituation of Ce for Ca in Bi-2223 superconductor. In first part, Bi 1.66 Pb 0.34 Sr 2 Ca 2 Cu 3 O x superconductor powder has been prepared via sol-gel method with different type of materials (nitrates and oxcides) and the effect of calcination temperature have been investigated. The XRD and SEM analysis and the result of the electrical resistivity and AC susceptibility measurement show that: for samples prepared with nitrates and calcinated in 790°c , the flux pinning force in the grain boundaries, phase formation of Bi-2223, electrical resistivity and critical current density are better than the samples prepared with carbonates and calcinated in 750°c . in second part, to investigate the effect of the partial substitution of Ca by Ce, Samples with nominal composition Bi 1.64 Pb 0.36 Sr 2 Ca 2-x Ce x Cu 3 O y (x=0.0, 0.2, 0.4, 0.6) have been prepared by Solid-State reaction method. The result of the AC suscebtibility measurement and electrical resistivity don’t show any transition to superconductivity state. After studying the reasons for these observations, we found that Ce element has a bad effect on the properties of Bi-2223 superconductors because the amount of the substitution of Ca by Ce is high.