Based on a simplified potential of a solute atom in the dilatation field of a kink, the general one-dimensional diffusion equation of solute atoms along the pipe of a dislocation with a moving kink was solved numerically. The instantaneous distribution of the concentration of solute atoms, instantaneous values of the dissipation of energy, of the mean damping coefficient and of the mean rigidity of an oscillating kink were calculated.Simplified approximate formulae about the mean damping coefficient and the mean rigidity were deduced from the numerical results obtained previously and in this paper, in terms of which the anomalous internal friction phenomena were explained semi-quantitatively.