The pseudo-quaternary Heusler alloys Co50Ni22Ga28:Fex (x＝0,1.5,2,2.5) single crystals have been synthesized. Excell ent pseudoelasticities were observed in compression, bending and torsion. At roo m temperature, the perfect pseudoelastic strains of 4% and 6.7% were obtained in the ［100］ and ［110］ directions of the Co50Ni22Ga 28:Fe2 single crystal under compression, respectively. The stre ss-strain curve for the Co50Ni22Ga28:Fe1.5 single crystals shows an indistinct platform on loading, and an intermar tensitic transformation occurs with unloading. The platform of the curve on load ing becomes clear and the intermartensitic transformation with unloading becomes indistinct at the high temperature of 100℃. Pseudoelastic strains of 5.5% wer e obtained in the ［001］ direction of the Co50Ni22Ga 28 :Fe2.5 single crystal. In addition, the single crystals show strong elastic anisotropy.