In this study the electrical theory of excitation propagation in excitable cell was investigated. The basic principals of linear cable theory were given and general differential equations concerning excitable cells were derived. The passive cable model simulation of axon was made through the programme of MATLAB7.0.4/ Simulink. In order to reach the realistic model, which is one of the main targets of the study, two simplified and revised models were used. A realistic wave shape was produced in MATLAB7.0.4/Simulink as the action potential wave shape spreading in axon. As seen in the results, the more length increases in the values of minimum and maximum amplitude, the weaker. They are as expected in the simplified model. When the simulation results of the two simplified and revised models compared, in the output of the revised model the minimum amplitude is seen to decrease. In the revised model, an ideal capacity element which we recommend was found. However, the most crucial result is that this capacity shortens the hyperpolarization period.