Abstract: It is important for recognition and utilization of temporal mechanism of auditory spike chain coding to recognize the timing characteristics of auditory spikes. But no simple stochastic process model can be used to describe the temporal pattern of auditory spike chain well, and existent physiological models such as Hodgkin-Huxley equations and Meddis's model, which are deterministic and continuous, can not be used to describe the discrete physical process and stochastic characteristics of spikes. Based on neurophysiology, a simple model of spontaneous auditory spike chain is established by specifying the neurotransmitters releasing pattern and the spike criterion. The model derives reasonable neurotransmitter release rate and external statistic character of spike chain at the same time. The model can also be used to explain qualitatively auditory phase-locked fire in response to tones. It can be a fundament of modeling stimulated spike chain.