A simple method for the sequence prediction of peptides capable of the in vivo stimulation of antibody production in mice without conjugation with protein carriers was proposed on the basis of literature data on the structure of T-helper epitopes active in vivo. According to this approach, a potentially active peptide should contain a nine-membered sequence with a hydrophobic amino acid residue in the first position and a positively charged residue in the ninth position. The efficiency of this approach was confirmed by the presence of such sequences in the previously described synthetic peptides with immune activities, by the application of this approach to the choice of immunogenic fragments within the sequences of various proteins that exhibited further the specific activity, and by the construction of immunogenic peptides on the basis of inactive natural sequences.