In the past, the names of ceramic fibers mainly include ordinary aluminium silicate fibers, high aluminium silicate fibers, zirconium aluminium silicate fibers, polycrystalline mullite fibers and polycrystalline alumina fibers. Their chemical compositions mainly include Al2o3, Sio2, Cro2, Zro2, Feo2 and so on. One of the bases for determining the qualifications of ceramic fibers is the corresponding chemical compositions and contents. With the wider application of ceramic refractory fibers and the increasing variety, new refractory ceramics with various chemical compositions and high technology have been successfully developed.