One of the highest reported tensile yield strength of HEAs at 1,023 K was 473 MPa for cast-type Al 10Co 25Cr 8Fe 15Ni 36Ti 6, which contained a FCC matrix with 46% L1 2 and 5% B2 phases by volume fractions 23, although its yield strength could surpass those of solid solution type superalloys such as 800H and Inconel617, it was weaker than advanced precipitation strengthened cast-type superalloys 24. However, the elevated temperature tensile strength of HEA could be limited by insufficient fractions and relatively low solvus of strengthening phases in HEAs 11. Recent studies have shown that coherent L1 2 phase could also be an effective strengthener in HEAs 11, 20, 21, 22, for example, L1 2 precipitation in Al 7 (Fe, Co, Ni) 86Ti 7 resulted a combination of high tensile yield strength (1,028 MPa) with large elongation (47.8%) at room temperature 20. In conventional precipitation strengthened superalloys, precipitation of coherent Ni 3(Al, Ti) L1 2 structured phase in FCC matrix can provide effective strengthening 19. The tensile strength of HEA could be degraded severely at elevated temperatures 4, 17, 18, for example at 1,023 K, the tensile yield strength of CoCrFeMnNi was lower than 100 MPa 17. Although some studies have reported tensile tested data of HEAs, there are only a few at elevated temperatures 3, 4, 10, 11, 12, 13, 14, 15, 16, 17. Most of the high temperature mechanical properties data of HEAs in literatures are from compression tests 3, 4, 10. The development of high-entropy alloys (HEAs) has broken through the frame of conventional alloys by exploring the vast composition space of multi-principle elements 1, 2, 3, 4, 5, 6, and their extraordinary mechanical properties have been a subject of interest, for examples, single-phase CoCrFeMnNi HEA showed high tensile strength of 1,280 MPa with elongation up to 71% at cryogenic temperature 7 the compressive strength could reach 2,240 MPa at 298 K for Al 0.5CoCrFe 0.5NiTi 0.5 HEA 8 and 1,520 MPa at 873 K for Al 0.5CrNbTi 2V 0.5 HEA 9 due to the presence of intermetallic phases, such as σ 8, B2 8 and Laves 9.