The paper deals with the formation of the dislocation structure of a heavy-wall pipe made of dispersionhardened Cu-based alloy and subjected to the uniform internal pressure. The increasing generation of shear dislocations and prismatic dislocation loops lead to the expansion of the plastic range with the pressure growth. With increasing size of strengthening particles and decreasing distance between them, the elements of the dislocation structure begin to generate more intensively similar to the strength properties of the material.