This paper deals with modeling of dynamic friction behaviors of a pneumatic cylinder. In previous research, the author have experimentaly investigated dynamic friction behaviors of pneumatic cylinders in the sliding regime and have showed that the measured dynamic friction behaviors can be simulated by the new modified LuGre model with a relatively good accuracy. However, the model cannot simulate accurately the effects of frequency of velocity variation on the friction force-velocity characterisitcs of the pneumatic cylinders. In this paper, the new modified LuGre model is revisied by varying some static parameters with frequency. Comparisons between simulation and experimental results show that the revised model is appropriate.