Results of a study of morphological changes of alpha2 and beta phases during superplastic deformation of Ti3Al are presented. A possible mechanism of the superplastic deformation of two-phase material is proposed on the basis of cooperative grain boundary sliding of two intersecting systems. Morphological studies of superplastically deformed titanium aluminides revealed the formation of two systems of stringers of alpha2 and beta phases. The orientation of the stringers or alpha2 and beta phases is at 30-60 deg to the tensile axis. Surface irregularities were found to be related to the intersection of stringers with the surface. The initially lathlike alpha2 phase in the super alpha-two alloy broke up into a more equiaxed morphology. 15 refs.