The electrical cardiac pacemaker model described in this paper simulates the most important functional properies of cardiac pacemaker cells. It is a minimum-parameter model which has a simple relaxation oscillator circuit as its main element. The electrical cardiac pacemaker model is analyzed in detail in order to show that its characteristic is similar to that of cardiac pacemaker cells. The main feature of the model is the possibility of controlling the time course phase 4 depolarization, the threshold level and the maximum level of repolarization, the rate of cardiac pacemaker. Emphasis is placed on phenomena of acceleration and frequency entrainment. This particular pacemaker model is very useful for the study of interactions between cardiac pacemakers and the description of the mechanism of arrhythmias.