Conductive polyaniline/zirconia (PANI/ZrO2) composites have been synthesized by in-situ polymerization of aniline in the presence of ZrO2 nanoparticles. The structure and morph- ology of composites were characterized by Fourier-transform infrared spectra (FTIR), thermo- gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscope (SEM). The conductivity was also investigated. The results showed that PANI and ZrO2 nanoparticles were not simply blended, and a strong interaction existed at the interface of ZrO2 and PANI. It was probably a composite at molecular level. The composites were more thermal stability than that of the pure PANI. XRD analyses confirmed PANI deposited on the surface of ZrO2 nanoparticles had no effect on crystallization performance of ZrO2 nanoparticles. Electrical conductivity measurements indicated that the conductivity of PANI/ZrO2 composites was much higher than that of PANI and the maximum conductivity obtained was 11.27S/cm at 15 wt% of ZrO2 nanoparticles.