Antimony doped tin oxide (ATO) is a typical p-type semiconductor and widely used due to its good properties such as electrical conductivity and transparency in visible range, while reflects infrared light. These features allow ATO to be used as transparent electrodes, heat mirrors and energy storage device, display panel. However, the use of tin oxide ceramics is limited by the low densification during sintering due to the dominance of non-densification mechanism such as surface diffusion or evaporation condensation. So, sintering agents such as Cobalt (II) oxide (CoO), zinc oxide (ZnO), manganese dioxide (MnO2) used to improve the densification of SnO2 by forming lattice solid solution or liquid phase. In this study, we studied the effect of the sintering agents. The antimony-doped tin oxide nano particles were synthesized by a sol-gel method. After sintering ATO with sintering agents such as MnO2 and CoO, sintered body characteristics were investigated by XRD, SEM, thermal conductivity, resistivity and interesting characteristic.