Shrinkage of a polymer occurs during the process of desorption but the classical models, as well as the analytical solutions, are obtained by neglecting this change in the dimension of the polymer. A new model, based on a numerical method with finite differences, is built up by taking into account not only the transport of liquid through and out of the polymer but also the shrinkage of the polymer which follows this desorption. Various beads of ethylene (vinyl acetate) copolymers with various contents of vinyl acetate ranging from 14 to 40% are used for the purpose, because the capacity of absorption of liquid depends largely on the content of vinyl acetate. The presaturated beads are immersed in water, and the transport of aniline used as the liquid is described by a transient diffusion with constant diffusivity. Various results are obtained, viz. the kinetics of desorption, the profiles of concentration of liquid developed through the polymer, and the change in dimensions of the bead. Moreover, it is shown that the analytical solution cannot be used properly when the amount of liquid absorbed exceeds ca 15%. NOMENCLATURE C = concentration of the liquid (g/cm3), Ci, = initial concentration of liquid, C1.,=concentration of liquid in the membrane of inital thickness Ar, located at the position j, at time t, CNj = concentration of liquid in the same membrane after time At, CI~,,= mean concentration of liquid in the external spherical membrane at time t, d = density of the liquid, D = diffusivity (cmZ/sec), G(j) = function defined by equation ( ), j, N = dimensionless numbers defining the position, 34, = amount of liquid located in the bead at time t, r = radial abscissa in the bead, R = radius of the empty bead, rJ., = abscissa at position ,/and time t, t = time, Ar, At = increments of space and time, Vj.,, V,,o~=volume of the spherical membrane of final thickness At, at the position j, at time t and infinite time, respectively, //N~ = volume of the spherical membrane of final thickness At, at the position j, after the elapse of time At, Vo. , = volume of the small sphere of final radius Ar/2 at time t, Vu. , = volume of the external spherical membrane of final thickness Ar/2, at time t.