Ba1-x Sr (x) TiO3(x = 0-0.5, BST) nanofibers with diameters of 150-210 nm were prepared by using electrospun BST/polyvinylpyrrolidone (PVP) composite fibers by calcination for 2 h at temperatures in the range of 650-800 A degrees C in air. The morphology and crystal structure of calcined BST/PVP nanofibers were characterized as functions of calcination temperature and Sr content with an aid of XRD, FT-IR, and TEM. Although several unknown XRD peaks were detected when the fibers were calcined at temperatures less than 750 A degrees C, they disappeared with increasing the temperature (above 750 A degrees C) due to its thermal decomposition and complete reaction in the formation of BST. In addition, the FT-IR studies of BST/PVP fibers revealed that the intensities of the O-H stretching vibration bands (at 3430 and 1425 cm(-1)) became weaker with increasing the calcination temperature and a broad band at 540 cm(-1), Ti-O vibration, appeared sharper and narrower after calcination above 750 A degrees C due to the formation of metal oxide bonds. However, no effect of Sr content on the crystal structure of the composites was detected.