Abstract: In order to improve the intencity of the gelation network of SiO<sub<2</sub< aerogels prepared by the sol-gel method,three modification methods of SiO<sub<2</sub< aerogels are studied.SiO<sub<2</sub< aerogels were produced from TEOS as silicon resources by sol-gel method and surface modification at ambient pressure.Fourier transform infrared spectrometer (FT-IR) results showed that the SiO<sub<2</sub< aerogels had good hydrophobic property.It is discovered that SiO<sub<2</sub< aerogels have better properties when the surface modification condition is: at <em<φ</em<(TMCS)=6% of hexane, surface modification time 24 hours.