In molten salt reactors, the interaction between fission products dissolved in the fuel salt with the structural alloys is a critical issue. Notably, the presence of tellurium (Te) poses a significant challenge by inducing intergranular cracks (IGC) for high temperature Ni-based alloys. Herewith, the corrosion behavior of high temperature Ni-based alloy GH3535 exposed to Te vapor (i.e. the test alloy with nominal doses of 1, 6, and 10 mg/cm² Te powders respectively were vacuum sealed in a quartz tube) at 700^oC for 150 h was assessed by means of scanning electron microscope (SEM), electron probe microanalyzer (EPMA), and transmission electron microscope (TEM), in terms of corrosion products and Te diffusion behavior. Results reveal that a dual-layered corrosion product was observed on the alloy surface after being exposed to Te vapor for 150 h at 700^oC. The outer telluride layer comprised Ni₃Te₂, Ni₃Te_2.07, and Cr₂Te₃, exhibiting a thickness directly proportional to the Te concentration. The inner ones represented a diffusion layer containing elongated Te-rich phases resulting from the inward diffusion of Te into the alloy matrix. Te diffusion was observed predominantly along grain boundaries (GB), penetrating to deeper regions and segregating there. It follows that the findings may provide a meaningful reference for understanding the Te-induced IGC, namely, this diffusion process led to a conspicuous depletion of Ni, Fe, and Cr at GB, thereby facilitating significantly the occurrence of IGC.