By selecting four different structure insulating materials of chinaware (containing 99% of aluminum oxide, Al2O3), polytetrafluoroethylene, organic glass and epoxide resin, the effects of different dielectric material and the same material with different thickness on the discharge characteristics have been studied under the same external excitation. The experimental results indicate that there exist significant differences of dielectric barrier discharge characteristics for different insulating materials and the same dielectric barrier layer with different thickness. The thin insulating materials with big dielectric constant (chinaware) can generate strong and uniform discharge easily. The rationality of the experimental results has been explained.