Superconductor Bi 2 Pb 1 - x Sn x Sr 2 Ca 2 Cu 3 O y (x = 0.0, 0.05, 0.08, 0.1, 0.2 and 0.3) samples were prepared by the conventional solid state reaction and analyzed by XRD, SEM, TGA and DSC and their resistivities were measured by standard ac four-probe method. When a small quantity of Sn (x < 0.1) was added, it was found from the SEM and XRD results that high-T c phase occurred preferentially and the critical temperature was elevated. With the results of XRD, EDX, DSC and TG, it was concluded that a small amount of Sn promotes the formation of liquid phase, which makes the weak link of grain boundary better. When a large amount (x =< 0.1) of Sn was added to the (Bi,Pb) 2223 system, however, the solid state reactions became more important than liquid phase-assisted reactions. Thus, the reaction rate decreased and there is no longer a significant role of tin on the formation of 2223 phase in that region (0.1 =< x =< 0.3).