Voltage-gated ion channels embedded in neuronal membranes are of great importance in the generation and propagation of electrical signals in the excitable membranes. These channels fluctuate randomly between open and closed states. Blockage of a given channel type is crucial to understand the impact of specific ion channel type on the neuronal dynamics for a given cell size. In this study, the impact of channel blocking on the spike propagation through myelinated axons is examined by using a compartmental stochastic axon model. Potassium channel blocking increases the transmission reliability while sodium channel blocking decreases it. On the other hand, potassium channel blocking decreases the thresold value for the electrical coupling between the nodes of Ranvier while sodium channel blocking increases it. Results also show that an increase in transmission reliability results in the increase in the spike train regularity. ©2010 IEEE.