Electrical break-down and erythrocyte membrane potential and blood viscosity and elasticity were studied on the model of experimental alloxan diabetes on days 7 and 14 of the experiment. Changed membrane elasticity was revealed in both terms, more evident changes in the second term, on day 14. Increased membrane electrical break-down and decreased potential were noted. Impairments of blood viscosity and elasticity are caused by changed membrane electrical properties. Increasing capillary pressure, these changes lead to an increase of microvessel walls permeability. S. This, alongside with the tissue hypoxia developing in diabetes, stimulates plasmatic saturation of basal membrane and proliferation of vascular endothelium.