Background. The drug cyphetrylin, hypothalamic hormone somatostatin analogue, was developed in N.N. Blokhin Russian Cancer Research Center at the Ministry of Health of Russia. The basis of this work is the idea of using cyphetrylin as a specific carrier of cytotoxic groups. Objective. Synthesis of cytotoxic cyphetrylin analogues in order to study the effect of the presence of cytotoxic agents on its antitumor activity. Results. The classical methods of peptide chemistry were used for 5 the new cyphetrylin analogues synthesis. The compounds have been obtained by the addition to the cyphetrylin Na-group of the cysteine or lysine Ns-group chlorophenacyl or hydrolyzed сyphelin (cytotoxic agent). Purification of the peptides was performed by column chromatography on silica gel. The purity of the obtained compounds was confirmed by elemental analysis, TLC, optical rotation angle data and HPLC. Preliminary studies of anti-tumor activity were performed in mice transplanted tumors: adenocarcinoma Ca755 breast and melanoma B16. Conclusions. New peptides - analogues cyphetrylin containing cytotoxic fragment have been synthesized, their structure and purity have been confirmed.