Abstract: PAHs from cooking fume(CF) and environmental tobacco smoke(ETS) were collected by simulating source emission in an environmental chamber.Then 18 PAHs were quantitatively analyzed to compare the difference of PAHs generated from different brands of cigarette and edible oil.Composition characteristics of these two sources were described and the chemical profiles were constructed.The CF samples were dominated by 2 or 3-ring species,but the ETS samples were done by 3 or 4-ring ones and Cor had a clear increase.Results indicated that Fluo, Pyr and Flu in CF and Flu,Phe,InP and BaA in ETS,content of which were relatively stable,can be used as signatures of indoor PAHs sources.The ratio of mass concentration of BaA/Chy,BeP/BaP and InP/BghiP between CF and EST differed greatly,which might be applied in the apportionment of exposure to indoor PAHs.The toxic equivalent factors(TEFs) were employed to estimate the health hazards of PAHs from cooking and ETS.Result indicated that the toxic effect of PAHs emitted(60 min) from 100 g edible oil under cooking was half of that of PAHs produced by 1 g tobacco.