Abstract
The problem of the motion of a large particle in the suspension of small (Brownian) particles in the gravitation field has been considered. The effect of the concentration of the small fraction on the established velocity of the large particle has been analyzed. A diagram showing the characteristic regions of the different behavior of the large particle in the suspension has been plotted. The case of the motion of the large particle in the suspension with an inhomogeneous height distribution of the small particles has been considered separately. It was shown that, in this case, large particles gather at a certain height depending on the determining parameters of the problem.