Abstract: Tungsten-based materials have good prospects as candidate materials for nuclear fusion devices and friction stir welding tools due to their high melting point and relatively excellent high-temperature mechanical properties.The microstructure and corresponding mechanical properties of as-received and annealed W-K alloy were investigated.The results show that the average grain size of as-received W-K alloy is 2.08 μm, with the average hardness values of 4.38 GPa.When the ambient temperature is up to 800 ℃, the ultimate tensile strength of as-forged W-K alloy is 423 MPa, accompanied with fracture elongation being 50%.The recrystallization temperature of the forged W-K alloy ranges from 1425 ℃to 1435 ℃.Recovery dominates inside the W-K material as the annealing temperature is lower than 1425 ℃.Compared with corresponding data of as-received samples, the average grain size increases by 22% to 2.23 μm while the average hardness decreases by 4%to 4.21 GPa with the tensile properties being characterized by the ultimate tensile strength reduces to 393MPa and fracture elongation descends to 34%as W-K alloy is annealed at 1425℃.When the annealing temperature is up to 1500℃, the recrystallization is finished along with grain coarsening.The average grain size is 178.17 μm, which is 84 times bigger than average grain size of original samples, meanwhile the average hardness drops by 18% to 3.60 GPa compared with as-forged samples.When the ambient temperature rises up to 800 ℃, the ultimate tensile strength of the W-K alloy annealed at 1500 ℃decreases dramatically to 208 MPa, and the fracture elongation is 44%.