On the basis of the charge discreteness, the quantum fluctuations fo the charge, current and energy in the mesoscopic metal dual rings are calculated by the minimum shift operator. The effects of the parameters on the quantum fluctuations are investigated. The results show that, taking account of the charge quantization, the quantum fluctuations of the current and energy are related not only with the parameters of the mesoscopic metal dual rings and Plank constant, but also with the charge discreteness.