In this thesis, dynamic flow resistance and acoustic properties of fibrous sound absorbing materials are simulated and measured. In the study, the poroelastic theory is used to simulate the dynamic flow resistance extending sound absorption coefficient, and carries two-microphone impedance tube measurement on the comparison. During the study, the dynamic parallel flow resistance is first derived from using Navier-Stokes equation in Laplace domain with specified boundary conditions. Secondary, flow resistances of fiberglass and rock wool sound absorbing materials are measured using air permeability test method, two-thickness method, and anechoic chamber method, then, the measured results are compared with that resulted from Tarnow’s parallel and perpendicular dynamic flow resistance simulations. Thereafter, acoustic properties of two kind of fibrous absorbing materials are measured by two-microphone impedance tube method, and the influences of material thickness and density on the acoustic properties such as acoustical impedance, complex dynamic stiffness, and sound absorption coefficient are also discussed. Afterward, complex dynamic stiffness, acoustical impedance, and sound absorption coefficient for the fibrous absorbing material with a permeable upper surface are derived using Biot’s poroelastic theory. Accordingly, the differences between the sound absorption coefficient simulated with the use of thickness, density, dynamic flow resistance, and that measured are discussed. It is learned that the spacing of fiber, fiber arrangement, density, and thickness are key factors for affecting the dynamic flow resistance and acoustical properties. In the study, it is found the simulated parallel flow resistance and the flow resistances measured by three measuring ways fall in between the values predicted by Tarnow’s parallel and perpendicular dynamic flow resistance simulations. Two-thickness method is superior to the other two kinds of measuring ways in Labs. The sound absorption coefficients simulated by applying the measured flow resistance and material properties are agree with that measured by two-microphone impedance tube method, in the low frequency region. And in the high frequency region, the simulated values have the differences with the measuring results but both have the same tendency. The sound absorption coefficients predicted by the results of the anechoic chamber method is proved much closer to the measured results.