A computational model, which includes both tunneling and thermal hopping mechanisms, has been applied to study the charge transfer in DNA (GC)(n) and (AT)(n) strands. The calculations revealed the crucial role palyed by the A or G NH2-group vibrations in the hole transfer in both types of strands. Charge-transfer rates in the two strands have been determined based on the molecular dynamics calculations. They are in good agreement with the available experimental data. The modeling appoach used here may be employed in the theoretical study of the charge transfer in natural and artificial DNA strands containing AT and GC pairs.