The mass spectra of two aromatic compounds have been analyzed using aerosol time-of-flight laser mass spectrometry (ATOFLMS). The results show that the single aerosol particles of aromatic compounds can easily form a molecular ion spectrum and molecule-ion reactions occur during desorption and ionization processes for hydroquinone. The results of real-time measurement on the size of ambient aerosol particles show that most of these particles are fine particles. Experimental results show that self-made aerosol time-of-flight laser mass spectrometer has important practical value for research and monitoring of atmospheric aerosol pollution.