DNA fragments of plasmid pSG1912 isolated from Streptomyces globisporus 1912 have been cloned into vector pUC19 in the E. coli cells. Stability of inheritance of hybrid derivatives in enterobacteria has been studied. The clones where recombinant plasmids are stably inherited have been chosen. The detailed restriction maps of cloned DNA fragments of pSG1912 have been constructed.