In　this　paper,　nanocrystal　titania　aerogel　was　prepared　through　sol-gel　extracted　by　supercritical　carbon　dioxide,　and　three　different　nanosized　particles,　newly　born　aerogel　particle,　titania　particles　preserved　in　the　form　of　aerogel　for　one　year　and　preserved　in　the　form　of　newly　born　aerogel　powder　particle　for　one　year,　were　characterized　by　FT-Raman,　FTIR,　and　FS.　The　degradation　of　methyl　orange　by　photocatalysis　is　regarded　as　a　model　reaction,　and　the　result　indicates　that　the　particles　preserved　in　the　form　of　aerogel　can　prevent　the　agglomeration　of　super-hydrophility　of　TiO2　surface　very　well　and　maintain　photocatalystic　activity　of　the　newly　born　particles.