The noise of an automotive brake system is known to be self-excited vibration caused by friction and various improvements have been incorporated. These improvements were made by many methods such as change of resonance frequency by changing the stiffness of the brake structure and change of the damping and friction characteristics of lining material. However, at present there is no definitive correction method. The purpose of this paper is to clarify the prevention method of self-excited vibration by fixing a carbon graphite lining with improved friction characteristics to one part of the original lining area. A heavy-duty truck with L-T type drum brake was tested and theoretical calculation was conducted using complex eigenvalue analysis by a multi-degree-of-freedom spring mass coupled vibration model.