The paper is concerned with the analysis of the present data as to the structure and properties of melittin, a biologically active peptide of bee venom, able to be inserted spontaneously into the natural and synthetic membranes and to destruct cells in micromolar concentrations. This property is a result of the peptide structure peculiarities. Attention is focused on the mechanism of melittin insertion into the phospholipid bilayer as well as on the possibility of its use to study the nature of protein-lipid interactions and formation of ionic channels.