The effect of SiO2 on sintering and dielectric properties of CaCu3Ti4O12 nanofibers were synthesized from the CaO-Cu2O-TiO2 and CaO-Cu2O-TiO2-SiO2 systems by a solegel electrospinning technique using polyvinylpyrrolidone was studied. Sintering temperature and morphology of CaCu3Ti4O12 nanofibers resulted largely dependent on selected system. SEM observations demonstrated that polycrystalline thinner CaCu3Ti4O12 nanofibers that could be obtained from the CaO-Cu2O-TiO2 system after sintering at 900 degrees C for 4 h. The electrospinning of the CaO-Cu2O-TiO2-SiO2 system lowered the sintering temperature of CCTO nanofiber to 800 degrees C. Novel composites based on doped or undoped CCTO fibers and Poly methyl methacrylate (PMMA) resin were prepared for measuring the dielectric constant of CCTO fibers. The calculated dielectric constant of pure (undoped) CCTO nanofibers were prepared in CaO-Cu2O-TiO2 system was about 148 at 103 Hz. An interesting phenomenon was found that CCTO fiber has different dielectric constant from CCTO bulk ceramic. Also, CCTO/PMMA composites containing doped CCTO fibers showed lower dielectric loss. (C) 2016 Elsevier B.V. All rights reserved.