Transfer of genetic material from tetraploid species, Triticum timopheevii Zhuk, resistant to diseases into common wheat Triticum aestivum L. has been carried out. Six common wheat cultivars were used. The process of hybrid forms stabilization have been studied in details; identification of Triticum timopheevii genetic material in genome of introgressive lines (2n = 42) resistant to leaf rust (Puccinia triti- cina Erikss.) has been carried out. Donors of rust resistance have been developed and the genetic control of the character has been studied. The resistance of obtained lines has been shown to be due to Lr genes, non- allelic to effective Lr genes from world collection.