A wrought nickel-base superalloy aimed to be used at above 1000℃ was designed by means of a statistical method. The alloy designed and investigated was based on the Ni-Cr-W-Ti-Al system, where the strangthening was achieved by a solid solution hardening superimposed with the gamma prime precipitation hardening. The new alloy exibited both excellent creep rupture strength and better corrosion resistance, and the rupture life of the alloy had reached up to 550 hr at 1000℃ under the stress of 4㎏/㎟. The main precipitates contributing to the elevation of high temperature strength were found to be the randomly distributed coarse alpha tungsten particles together with the uniformly distributed fine gamma prime particles. In this alloy. the carbide of M_(23)C_6 type was appeared to be stable precipitate after a long time heat treatment at 900℃ whereas that of M_6C type was stable at 1000℃.