Abstract: Experiments were carried out to investigate the absorption and reflection of electromagnetic waves (range from 50MHz to 3GHz) by plasma array panels.The results show that plasma has the features of strong absorption and weak reflection on the incident electromagnetic waves.On the scope of experimental frequencies (50 MHz to 3 GHz),plasma array panels absorb all the incident waves more or less with the values between 9.9 and 25.6 dB,but there're several absorption peaks in different frequency bands.Additionally,plasma can reflect electromagnetic waves,but the value is very low,between 0 and 3.5 dB.The results are of great significance to the construction of plasma stealth barriers.