Poly(ethylene terephthalate) (PET)/SiO2 composite micro/nanofibers were successfully prepared by a laser melt-electrospinning system. The fibers with diameter ranging from 500 nm to 7 mu m were obtained. The effect of laser current and applied voltage on the fibers morphologies was investigated by scanning electron microscopy (SEM), and the results showed that the relationship of process parameters and fibers diameter was complicated. The EDS analysis confirmed the presence of SiO2 in the PET fibers matrix. The crystallization behavior of the electrospun PET/SiO2 micro/nanofibers was investigated using X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC), and it was found that the as-electrospun fibers exhibited an amorphous phase. After heat-treatment at 120 and 160 degrees C for 1 h, respectively, the fibers showed a high crystallinity. The thermal properties of fibers were studied using thermogravimetry-differential thermal analysis (TGDTA), and showed the electrospun PET/SiO2 composite fibers was not effective difference of thermostability compared with PET fibers when used for fibers materials. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012