The adsorption of NO on [Co+Mg(Sr)]/ZSM-5 zeolites with different [Co+Mg(Sr)] contents was studied by means of FTIR spectroscopy. The dominant NO species adsorbed on [Co+Mg(Sr)]/ZSM-5 was found to be in a dinitrosyl form, as demonstrated by the IR bands at 1 813 and 1 896 cm-1. NO was adsorbed in a mononitrosyl form as shown in the region of 1 937-1 939 cm-1 as a minor species. Samples [Co+Mg(Sr)]/ZSM-5 showed a new band near 1 858 cm-1(w) attributable to the species of Co3O4-NO. It was found that zeolite [Co+Mg(Sr)]/ZSM-5 exhibits superior performance characteristics for SCR of NO molecules, and is promising as a useful catalyst. The typical catalyst [Co+Mg(Sr)]/ZSM-5 for SCR resulted from the collaboration of the metal alkalinity and the ionic radius of the metal(such as Mg or Sr).