The microstructure evolution as well as primary creep properties of Ir-Nb-X(X=Hf, Ta, Ti) ternary alloys was investigated. The fcc/L1(2) two-phase structure with the cuboidal L1(2) precipitates was observed in all the samples investigated. Compressive creep property of the sample with the most promising microstructure was carried out at 1800 degrees C under 137 MPa. Combining the results obtained, the potential of these alloys for the development as new high-temperature materials was discussed.