Abstract
Some structural changes are observed in the sample of Bi1.7Pb0.3Sr2Ca2Cu3Ox. Temperature dependebce x-ray diffraction demonstrates that there are two lattice softness in low temperature range, one at about 220 K, another at about 120 K, and two lattive expansions at high temperature range, one at 300 oC and another at 750 oC. Thermal analyses support the results of x-ray diffractio. we suggest that these changes in crytal structure related with the two different blocks in the titled compound.