AbstractThe kinetics of the appearance of the superconducting 123 phase in partially melted at 1200 °C YBCO samples has been studied in the temperature range of low undercoolings from 1040 °C to 920 °C. An EDS analysis of the phases formed at different stages of the cooling of the melt has been performed and the experimental conditions for crystallization of 123 phase with finely dispersed 211 phase in it have been established. The results have been interpreted in terms of the classical theory of nucleation and they have been applied to the MTG process for formation of highly textured YBa2Cu3Oymateria