In this study, the diffusion behavior of Te in alloy GH3535, a Ni-Cr-Mo alloy designed specifically for the Chinese Thorium Molten Salts Reactor, was investigated by thermally exposing alloy samples in Te atmosphere at 800oC. Subsequently, room temperature tensile tests were conducted on the Te diffused alloy samples to study the degradation of mechanical properties and cracking behaviors of the alloy. Results show that Te preferred to diffuse along the random high angle grain boundaries in the alloy, and no Te was present in Σ3 grain boundaries. Cr-Te intermetallic compounds were observed at the grain boundary and the matrix/intergranular carbides interface, whereas more complicated mixture tellurides were identified at the grain boundary triple junctions. Under tensile stresses, the grain boundaries contained Te exhibited intergranular brittle cracking, resulting a reduction in the ultimate tensile stress of the alloy.