The effects of YBa2Cu3Oy (YBCO) doping into Bi2Sr2Ca2Cu3Ox (BSCCO) on superconducting properties are investigated. With increasing doping concentrations of YBCO from 2 to 20 wt%, Tc of the samples decreases from 100 to 80 K. However, scanning electron microscope and X‐ray diffraction results indicate that both BSCCO (Tc > 100 K) and YBCO (Tc > 90 K) exist in the samples. The decrease of Tc of the samples may be due to the deviation of the oxygen content of the BSCCO from the optimum one for high Tc, which is caused by the YBCO doping.