Al2O3-SiO2 composite nanofibers were fabricated by calcining the precursor fibers obtained through sol-gel processing and electrospinning technique. Thermogravity-differential scanning calorimeter, powder X-ray diffraction, X-ray fluorescence analysis, scanning electron microscopy, transmission electron microscopy, and thermal conductivity instrument were employed to characterize the fibers. Upon calcining the precursor fibers at 1300 degrees C, continuous Al2O3-SiO2 composite nanofibers with diameter of about 300 nm can be obtained. The calcined fibers had low thermal conductivity, which might favor their application in high-temperature insulation areas.