Sequences of tension-fatigue tests were performed on copper polycrystal sheets. For the angle between the two successive loading directions, two typical values (0degrees and 45degrees) have been chosen. The effect of strain path change on subsequent initial work hardening rate and saturation stress has been investigated. The strain rate for the tension tests was 5 x 10(-3) s(-1), while the fatigue tests were performed under constant plastic strain amplitude control with different values (6 x 10(4), 1.5 x 10(-3), 3 x 10(-3)). The dislocation microstructure was observed by transmission electron microscopy after mechanical testing. Under the present conditions, it was found that the strain amount of pre-loading in tension has an effect on the initial cyclic hardening rate, while it has almost no effect on the saturation stress of subsequent fatigue behaviour, no matter the value of the angle between the two successive loading directions. The observed increase of the reloading axial stress is higher for the Phi=45degrees case than for the Phi=0degrees case, which is due to the latent hardening effect of dislocation developed in pre-deformation on newly activated slip systems. The correlation between mechanical properties and microstructural. observations is discussed.