Abstract: Abstract：A Sol-gel method was used to prepare Pb Sr1-TiO3 powder，in which the contents of Sr and Pb were different(=0．4，0．5，0．6)．Powders were annealed at 900 oC．Their crystallographic structures were characterized by X-ray diffraction．XRD patterns showed the diffraction peak was splited into two and the distance of the two peaks(101／1 10)gradually increased with increasing molar ratio of Pb／Sr．The lattice parameters were calculated
from the split peaks of(001／100)．Experimental resuhs show that lattice constant ratio c／a and the cell volume increase with increasing Pb content，indicating a phase transition from a cubic phase to tetragonal phase．

Key words: Pb Sr1-TiO3；Sol-gel method；phase transition；XRD(X-ray diffraction)