Abstract: A Study on Mass Spectra of PropenonesPeng Jiarou; Pang Jihai; Liu Yong; Liu Maozi (Analysis & Computation Center, Beijing Medical University, Beijing 100083,China) Lu Yixian;Hu Dun;Cai Mengshen (School of Pharmaceutical Sciences,Beijing Medical University, Beijing 100083,China) Abstract:Seven propenones were determined by EI,HREI and EI-CA-MIKES(Collision Activited Mass-analyzed Ion Kinetic Energy Spectrum). Their main fragmentation of mass spectrometry was discussed in comparasion with that of typical chalcones. Keywords: propenones,chalcones, EI-CA-MIKES