It has been shown that two main Cu sites present in ion exchanged Cu-ZSM-5 which differ in positive charges on the Cu2+ ion, exhibit substantially different redox properties and reactivity towards NO molecules investigated by IR spectra of adsorbed NO and CO, and Cu+ emission spectra. The Cu ion with low positive charge (tested by electron density transfer from NO molecule to the cation) is assumed to be balanced by a low negative charge, i.e., a single framework Al atom. This Cu site preferably forms Cu+ dinitrosyl complexes and exhibits high stability of Cu+ even in oxygen at high temperature (720 K) compared to the other Cu ions with higher positive charges, which are suggested to be balanced by two framework Al atoms. A decisive role of local negative framework charge adjacent to the cation as well as total negative framework charge given by Si/Al ratio for the redox properties and reactivity of the Cu ions has been indicated.