Abstract: Creep brittle rupture along the weld interface is a typical premature failure characteristic of dissimilar metal welded joints,In this paper,the creep strain distribution of CrMoV dissimilar metal welded joints was analysed by means of FE calculation, thermostable moire and creep rupture tests. It is concluded that the stress triaxiality (σ_h/σ) in the low-strength base metal adjacent to the interface is a predominant mechanical parameter controlling the premature brittle rupture of the joints.