Optically stimulated luminescence(OSL) is the luminescence emitted from a semiconductor during its exposure to light.The OSL intensity is a function of the total dose absorbed by the sample.The dose-rate dependence of the OSL signal of the semiconductor CaS doped Ce and Sm was studied by numerical simulation and experiments. Based on a one-trap/one-center model,the whole OSL process was represented by a series of differential equations. The dose-rate properties of the materials were acquired theoretically by solving the equations.Good coherence was achieved between numerical simulation and experiments,both of which showed that the OSL signal was independent of dose rate.This result validates that when using OSL as a dosimetry technique,the dose-rate effect can be neglected. Optically stimulated luminescence (OSL) is the luminescence emitted from a semiconductor during its exposure to light. The OSL intensity is a function of the total dose absorbed by the sample. The dose-rate dependence of the OSL signal of the semiconductor CaS doped Ce and Sm was studied by numerical simulation and experiments. Based on a one-trap / one-center model, the whole OSL process was represented by a series of differential equations. The dose-rate properties of the materials were acquired theoretically by solving the equations. Good coherence was achieved between numerical simulation and experiments, both of which showed that the OSL signal was independent of dose rate. This result validates that when using OSL as a dosimetry technique, the dose-rate effect can be neglected.