The influence of relaxation of stresses occurring during the beta --> alpha transformation of tin on the kinetics of the transformation has been studied. It has been shown that a change in conditions of stress relaxation brings about a change in (5 x 10(-6) < h < 3 x 10(-3) m) and by introducing impurity atoms of Ge (0.1 < c < 0.3 at.%). The mechanism of the influence of stress relaxation on the transformation kinetics has been suggested.