In order to study the temporal behavior of the low-amplitude grey spatial solitons in two-photon centrosymmetric photorefractive crystals, the expressions of time-dependent space-charge field and dynamical evolution equation are obtained, based on the two-photon photorefractive effect in centrosymmetric photorefractive crystals. The temporal behavior of the intensity profiles and the intensity full width at half maximum of grey solitons are obtained by numerical method. The results indicate that the intensity width of spatial solitons generated at the beginning decreases monotonously to a minimum value until steady state. Within the same propagation time, the higher the ratio of solitons′ peak intensity to the dark irradiation intensity is, the shorter the intensity full width at half maximum of grey solitons is. Dynamical evolutions of the low-amplitude grey spatial solitons are simulated numerically at different time.