In this study, protective Ti coatings were deposited on the CoSb3 substrate by DC magnetron sputtering to prevent the sublimation of Sb. The microstructure of Ti coating was observed by SEM and AFM. The thermal aging behaviors of coated CoSb3 samples were investigated through accelerated aging at 650 C for 24 h. The results indicated that Ti coatings were columnar crystals and body-centered cubic structure. The preferred orientation of Ti film was along the crystal plane of (002). The thickness of Ti film increased with the deposition time increasing. The weight loss decreased with the thickness of Ti coating increasing. Compared with the uncoated CoSb3 material, the degradation of thermoelectric properties for coated CoSb3 samples decreased slowly after accelerated thermal aging test. (C) 2014 Elsevier B.V. All rights reserved.