Abstract: Cellulose fiber，polypropylene fiber，polyester fiber，glass fiber，and polyacrylonitrile fiber were used to prepare 5 fiber-reinforced silica aerogel composites by sol-gel method，and they were characterized by SEM，BET，and CA.Results indicated that the polyacrylonitrile fiber-reinforced silica aerogel composite had the smallest shrinkage percentage（only 9%） and the largest specific surface area（583 m2/g）.The smoothness of glass fiber composite was the best.The transparency of polypropylene fiber composite was better than the others.The differences between the fibers affected their binding degree to the aerogel particles，and thus affected the composite′s transparency，specific surface area，and shrinkage percentage，but the hydrophobicities of all the 5 prepared composites were good.

Key words: silica aerogel, fiber, hydrophobicity