Abstract: The volatile components in Prunella vulgaris were extracted by gas purge micro-extraction technique, and then analyzed by gas chromatography-mass spectrometry, the relative contents of individual constituents in the volatile components were determined by peak area normalizing method, the volatile components of root, branch, leaf and flower for Prunella vulgaris were compared by chemical method and principal component analysis. The results showed 145 peaks were isolated in Prunella vulgaris, 98, 98, 98 and 124 components were identified in root, branch, leaf and flower, which accounted for 66.53%, 91.24%, 89.32% and 84.87% of the total peaks in each part. Flower mainly contains alkanes (29.01%) and N, O-compounds (12.17%). Aldehydes (20.66%、21.18%) and phenols (13.23%、19.8%%) were the main contributing components in root and branch. Alcohols (26.79%) and aldehydes (15.15%) were the main contributing components in leaf. The results showed that the chemical components were a great difference between the flower and the other parts. This study provides reference basis for development and utilization of Prunella vulgaris in food and medicine.