Abstract: In order to study the acoustic insulation property of glass fabric, three different types of glass fiber plain weave fabrics EW100, EW200 and EW300 with different fabric densities, linear densities, layer numbers were collected for the tests and analyses. The acoustic insulation properties of these fabrics were measured and compared by the reverberation room-slience room method. The effect of material parameters such as fabric square density, thickness, air-permeability, filament number, etc on the acoustic insulation properties was analysed. The results showed: with the increase of fabric square density，thickness, filament number and the reduction of air-permeability, its acoustic insulation performance increases. The acoustic insulation property of glass fiber fabric in high frequencies is superior to that in middle-low frequencies, and the acoustic insulation property of glass fiber fabric is not only related with the fabric surface density, but also with its air-permeability. When the air-permeability is good, the sound reduction index of glass fabric has a certain plus capability toward the square density, while the air-permeability is poor, the contribution of the sound reduction index generated by sound wave absorption of its material interior is much greater than that of surface density.