Deformation behavior of Zr-based alloys by forging under conditions of α↔β phase transformations was considered as applied to model samples and real semi-products. Model samples were deformed by uniaxial compression at temperatures of β- and (α+β)-regions of the phase diagram Zr-Nb. Mechanisms, responsible for plastic deformation of alloys by different temperature-rate regimes, were determined on the basis of textures, arising in deformed samples. Among these mechanisms there are crystallographic slip in grains of β-Zr and α-Zr as well as mutual displace¬ments of crystallites along interphase boundaries. The latter mechanism sharply intensifies under conditions of α«β phase transformations and lies in the basis of superplasticity. An input of each mechanism into plastic deformation of material depends on the temperature-rate regime of compression and determines its anisotropy.