The never fiber has been defined as a long neuronal process,which works as a relatively sample relay line between neurons,insuring the conduction of information from the cell body to the nerve terminal.By large numbers of fibers,ramifications and synapses,neurons are not only connected with each other but also with their receptors,thus constituting a complex neural signal processing system.The evidence for that pattern of interspike interval (ISI) series contains information is gaining attention as a new theoretical and experimental approaches.Many phenomena suggest that the pattern of ISI series is not always conducted faithfully along the axon.So the function of nerve fibers,especially non-myelinated fibers (C-fibers),need to reexamine.The present study is to be done with single C-fiber recording techniques in rabbits' saphenous nerves.