Secretion vectors were constructed in which a synthetic gene of human epidermal growth factor (hEGF) joined with a gene coding for the leader peptide to one of the E. coli outer membrane major proteins (OmpF) is controlled by tac promoter. The increase of the hEGF yield was achieved by the multiplication of the gene copies. The hEGF in bacterial cells was secreted into periplasm. The recombinant protein was isolated by means of reverse phase chromatography as almost homogenous preparation (greater than 98%), the yield being 7 mg/l bacterial culture. The sequence of twenty-five N-terminal amino acid residues of the isolated hEGF coincided with that of the natural protein. The preparation proved to be biologically active.