The carriers in automotive catalyst converter are ceramic. The iolite content of such carrier is usually more than 95%. The heat expansion coefficient of iolite is approximate to 0, so it can endure high temperature (its melting point: 1400℃) and heat impact up to 1200℃, and its mechanical strength increases with the rise of temperature. The carrier is usually of honeycomb shape, and has thin walls and certain strength as required. The number of holes of a carrier shall also meet certain requirements, such as the current “400 holes per square inch” or more. The cross section of carrier is circular, elliptical, or of raceway shape or other shapes, which is determined and adjusted mainly in consideration of the automobile model.