The gas pressure drop of rotating packed bed (RPB) is an important indicator for measuring its performance. This work examines pressure drop using air-water system in which the RPB can be operated from 0 to 800 r/min and the gas flow rate can be ranged from 200 to 1100 m(3)/h and the liquid flow rate can be varied from 0 to 9 m(3)/h. Results show that the pressure drop of dry bed increases with increase in gas flow rate and rotor speed while that of wet bed is the same without flooding. The phenomenon of flooding occurs in range of lower rotor rate when the gas flow rate is large enough. The pressure drop of dry bed is lower than that of wet bed when the rotor rate is low, vice versa counter. This work lay the foundation for the design and application of RPB industrialized on both the theoretical and experimental side.