On the basis of quantitative characteristics (Kd, Km, Gibbs energy values) for the interaction of oligonucleotides with template and primer site of eucaryotic and procaryotic DNA polymerases, a general model of template-primer interaction with these enzymes was suggested. The interactions of AMV- and HIV- reverse transcriptases with various 5'-derived oligonucleotides and with human DNA polymerase alpha and Klenow fragment are compared. The results obtained suggest a method to improve selectively the affinity of an oligonucleotide primer to RNA template with AMV- and HIV-reverse transcriptases.