The optimal composition for synthesizing the high-T-c phase 2223 in the Pb-doped bismuth oxide system has been presented. It was shown by using DTA, SEM (EDAX) and XRD that a single 2223 phase could be fabricated when the sample of a Bi2.1-xPbxSr1.9Ca2.05Cu3.0Oz, where x is between 0.2 and 0.3 (not including the loss of Pb), was sintered at 850-860 degrees C. It was also indicated that excessive Pb is more effective than excessive Cu in promoting the formation of 2223.