Abstract: The catalyst regeneration system is an important part of the continuous catalytic reforming unit.Carbon content of the spent catalyst in the continuous catalytic reforming unit often fluctuates between 2% and 6%, which affects seriously the operation adjustment of the catalyst regeneration system.It is found that the presence of more aromatic components in the catalyst is the cause of this fluctuation.Through improving the analytical method, carbon content of the spent catalyst that is baked at 100℃ for 2.0 h will no longer fluctuates greatly, which ensures the smooth operation of the system.