Abstract: A one-dimensional model is proposed for sound absorption of a porous metal plate with finite thickness at high sound pressure levels(SPLs),where the sound pressure is linear with the particle velocity at the back of the plate.In order to predict nonlinear acoustic performance,the particle velocity inside the porous plate is solved by a linearization and finite difference method.Acoustic measurement for two porous metal plates was performed in an impedance tube;the normal surface impedance and sound absorption coefficient at different SPLs were obtained.Good agreement between the experimental and theoretical results validates this model.The method developed here can be also applied to other rigid porous materials.