The ion-channel formation of outer membrane protein F (OmpF) can be achieved in phosphatidylcholine bilayer membrane modified on a pyrolytic graphite electrode, which makes it possible to sense the porin functionality conveniently with an electrochemical technique through the change in the redox peaks currents of an electroactive marker. The effect of ionic strength, pH on the ion permeability of OmpF and the effect of the protein concentration on the ion-channel formation have been thus examined. This study may provide a simple and rapid way to probe other similar biological processes within natural cellular membranes.