Objective To explore the mechanisms of Artemisia argyi burning and moxibustion photo-thermal effect.Methods N-alkanes were obtained by gradient solvent extraction and silica gel column chromatography elution from 1, 3 and 5 years’ Artemisia argyi produced in QiChun, Hubei and analyzed by gas chromatography mass spectrometry (GC-MS).Results The n-alkane contents of 1, 3 and 5 years’ Artemisia argyi were 318.65, 528.23 and 394.20μg/g, respectively. A total of seventeen kinds of n-alkanes were detected from the Artemisia argyi of three kinds of years. The 31 carbon alkane content was highest in all of them. Because N-alkanes affect the temperature and stability of Artemisia argyi burning, it may be the material basis for explaining “worrying seven years’ diseases seek 3 years’ Artemisia argyi”.