Abstract
In classical mechanics, a mechanical system volume over time in general is changing. But possibly has certain mechanical quantities, maintains invariable in the rate process, this kind of mechanical quantity is called the conservation quantity. In the quantum mechanics, between the conservation quantity and the system symmetry has the close relation. In addition, when uses the quantum mechanics deals with each kind of concrete issue, can the strict demander be extremely few, but with the aid in the symmetrical system's analysis, does not need to solve the Schrödinger equation strictly, often may draw some very important conclusion. In this article summary analysis quantum mechanic's conservation quantity and the symmetry, and have analyzed between symmetrical and the conservation quantity relations. And has involved, in quantum mechanics symmetry three deductions (conservation law, energy degeneracy, selection rule), Schrödinger equation symmetry and law of conservation of energy, mechanical quantity along with time evolution and symmetrical relations, all with granule system's symmetrical analysis.
Keywords：Quantum mechanics；Symmetry；Conservation quantity； Microscopic system； Space and time symmetry.
