Dermorphin is a hepta peptide(H-Tyr-DAla-Phe-Gly-Tyr-Pro-Ser-$NH_{2}$)with exceptionally potent and long-lasting peripheral and central activity. Dermorphin analogues, dermorphionyl(DMP)-Lys-$NH_{2}$ and DMP-Lys-Lys-$NH_{2}$ have been prepared in order to examine the effect of opiod activity. Dermorphin analogues were synthesized by the solid phase method. The crude peptide was purified by gel filter on a Sephadex LH-20, characterized with HPLC and amino acid analyzer. Analgesic potency was estimated by writhing syndrome method and Randall-Selitto method. As a result, dermorphin analogues have lower potency than that of morphine.