The application of Inductively Coupled Plasma (ICP) can cause a wide range high density plasma and has great advantages in electromagnetic wave attenuation. Studying the process of interaction between ICP and electromagnetic wave, we established the electromagnetic wave propagation in inhomogeneous plasma, adopted hierarchical model for the diagnosis of the interaction of plasma and electromagnetic wave, and studied the electromagnetic wave attenuation under different conditions of input power. The experiment method of inductively coupled plasma for attenuation electromagnetic wave was proposed. Based on the model of plasma covering over the metal plate, the arch system for measurement of microwave reflectivity of plasma was established. The interaction of closed-plasma and electromagnetic wave with a bandwidth of 4-8 GHz was studied, the effect on microwave reflection of different rf power was evaluated analyzed, and the experimental measurement and calculation results were analyzed. The experimental results show that the inductively coupled plasma attenuates the electromagnetic wave in 5.92-6.8 GHz band obviously by power regulation.