Abstract: A Study on Mass Spectrometry of Imidazo Quinoline and Imidazo QuinoxalineYang Yinghua; Zhang Xueming(Jinn Import and Export Commodity inspection Bureau,Changchun 130062, China)Abstract:In this paper, five EI mass spectra of imidazo quinoline and imidazo quinoxalinehave been reported. Their fragmentation mode have explained through HR data andrnetastable transition.Keywords: imidazo quinoline, imidazo quinoxaline, high resolution , metastable.