Taking into account the variability of coupling strength with increasing time,we present the nonlinear stochastic dynamical model of neuronal population,where the average number density is introduced as a distributed coding pattern of neuronal population.In the absence of external stimulus,numerical simulations indicate that the synchronized activity of neuronal population increases the coupling strength among neuronal oscillators; the coding pattern of the average number density is related to coupling configuration among neural oscillators.These studies also show that the variability of the coupling strength displays a slow learning process in the weak noise,but the coupling strength exhibits transient process in the strong noise.Numerical simulations confirm that the higher the coupling level is,the larger the synchronization of neuronal population is,and the stronger the coupling strength is.