Abstract: In the inductance-coupling mesoscopic circuit, by taking account of the charge discreteness, a method for calculating quantum effects is proposed in the new Fock space that is formed by the eigenstate of charge operator. In this method, by introducting the minimum shift operator, the system Hamilton and the physics current are expressed according to the charge operator and the ladder operator, and the quantum fluctuations of the charge, current and energy are calculated directly by the character of the ladder operator. The obtained results are related with self-inductance closely. In designing the quantum circuit and the nanoelectroic devices, the considerable factors are given for the quantum noise reduction.

Key words: mesoscopic circuit, inductance-coupling, charge discreteness, quantum fluctuation