The thermal expansion of superconducting Bil.sPb0.4Sr2Ca2Cu30• (BiPbSrCaCuO) and its oxide components Bi203, PbO, CaO and CuO have been studied by high-temperature dilatometric measurements (30-800 ~ The thermal expansion coefficient for the BiPbSrCaCuO superconductor in the range 150-830 ~ is ~=6.4 x 10 -6 K -1. The temperature dependences of AL/L of pressed Bi203 reveals sharp changes of length on heating (/-1 =712~ and on cooling (T2=637~ and T3=577 ~ caused by the phase transition monoclinic-cubic (7-1) and by reverse transitions via a metastable phase (T2 and "/'3). By thermal expansionmeasurements of melted Bi203 it is shown that hysteresis in the forward and the reverse phase transitions may be partly caused by grain boundary effect in pressed Bi2Oa. The thermal expansion of red PbO reveals a sharp decrease in AL/L on heating (T~=490~ related with the phase transition of tetragonal (red, a=0.3962 nm, c=0.5025 nm)-orthorhombic (yellow, a=0.5489 nm, b=0.4756 nm, c=0.5895 nm). The possible causes of irreversibility of the phase transition in PbO are discussed. In the range 50-740~ the coefficient of thermal expansion of pressed Bi203 (~m=3.6 x 10 -6 and ~c---16.6 x 10 -6 K -~ for monoclinic and cubic Bi203 respectively), the melted Bi203 (0~m=7.6 x 10 -6 and ~0=11.5 x 10-6 K-~), PbO (~t=9.4 x 10 -6 and 0~or=3.3 X 10-6K -1 for tetragonal and orthorhombic PbO respectively), CaO (~=6.1 x 10 -6 K -1) and CuO (==4.3 x 10 -6 K -~) are presented.