The work was performed on 40 rabbits. After injection of the blood system with Gerota's mass 120 mu horizontal sections were cleared after A. M. Malygin and stained with hematoxylin and eosin after Van Gieson. It was shown that within 1--3 weeks of staying in small cages the animals had dilated vein all areas of the brain under investigation. Within 4-12 weeks there appeared deformity, sharp sinuosity, disorders in usual orientation of vessels. Within 13-16 weeks of hypokinesia both qualitative and quantitative changes in blood vessels became more pronounced. It was also shown that readaptation for 1--3 weeks after 4--13 weeks of hypokinesia failed to repair the normal structure of blood vessels of the brain and that in all the parts under study the reactions of the circulatory bed structure to hypokinesia were of the same type.