Summary: This paper summarizes the main results of analyses of electroencephalograms in rats with genetic predisposition to absence epilepsy (WAG/Rij rat strain). Properties of epileptic activity are described in time and frequency domains. The dynamics of epileptic activity is investigated, as well as changes in electroencephalogram structures prior to epileptic discharges. Physiologic interpretation of the investigated phenomena helps in better understanding the nature of the investigated phenomena.