In this paper, the CdO nanoparticles were prepared by chemical reduction method. Then, the CdO nanoparticles were doped in the Bi_1.64Pb_0.36Sr₂Ca_2-xCd_xCu₃Oy with
 x = 0.0, 0.01, 0.02, 0.03, 0.04, 0.1 superconductor.  The samples were synthesized by the standard solid-state reaction technique. The structural properties, microstructure and morphology of the samples have been studied by XRD, SEM and TGA-DTA. After synthesizing the samples and observing the Meissner effect, the study of the crystallography, critical current density (Jc), critical temperature (Tc), SEM, and Thermogravimetry-Differential thermal analysis shows of samples have been down. The results of the critical current density measurements show that the sample with x = 0.01, with annealing time 270h and the size of 16nm, has the maximum JC. Although the critical tempeprature increases with subittiution of Cd for Ca but the results of the critical temperature measurements of the samples with the CdO nanoparticles reveal that no remarkable increasing in the critical temperature was observed. With increasing annealing time, critical temperature and critical current density of all samples increases too.