8-oxo-7,8-dihydroguanine (8oxoG) is one of the most important base lesions formed during oxidative damage of DNA. The aim of the present research was to investigate the effects of DNA concentration, G content, and the nature of oxidizing species on the kinetics of 8oxoG in model DNA solutions by using HPLC. The experimentally obtained yields of 8oxoG were typically in the range of 2-2.5% of total concentration of guanine. The ratios of the rate constant of hole diffusion in DNA to the rate constant of conversion of the hole into 8oxoG (kd/kr) were calculated from the experimental data using the diffusion model of charge transfer in DNA to be in the range of 200-300, in agreement with previously reported kd/kr ratios in the duplex DNA oligonucleotides (GGA)n or (GGTT)n. Our current diffusion model cannot satisfactorily explain the absence of the G content dependence of the 8oxoG yields, which indicates that a more advanced model is required.