Abstract:Glass fiber paper is a kind of excellent non-flammable, heat and sound insulation, filterable materials, which is widely used in high-speed rail, aerospace and marine areas. This paper mainly explored pore diameter distribution, air permeability, heat and sound insulation property of glass fiber paper prepared of beating by wet process with different diameter fiber . The results show that with the increase of content of fine glass fiber of paper, the average pore diameter and air permeability decrease firstly and then increase ,the thermal conductivity of paper decrease firstly and increase subsequently, the sound transmission loss of paper increase firstly and decrease subsequently. With the ratio of 50% crude fiber and 50% fine fiber, the glass fiber paper had the best heat and sound insulation properties.