Abstract: The absorbing structure made of an aluminum fiberboard and a cavity on its back has clear resonance absorption characteristics. The resonant frequency and amplitude are related to the cavity depth, surface density, degree of compression, and the mounting. Acoustical parameters of an aluminum fiberboard, relative acoustical impedance ζ and ratio of the equivalent thickness l with equivalent porosity, can be obtained through an absorption coefficient spectrum measured in a standing wave tube. In general, acoustical characteristics of an absorbing structure can be studied using the common theory based on a micro,perforated panel resonance absorbing structure. The aluminum fiberboard cannot be regarded as a "local reaction" material because of the even spread of the aluminum blanket. The absorption property can be improved when partitions close to each other are installed in the back cavity.