Perilla frutescens (Lamiaceae) is a widespread medicinal plant traditionally used in China to treat several diseases. In order to enlarge the medication parts, the constituents of essential oils which extracted with microwave-assisted hydrodistillation (MAHD), ultrasound-assisted extraction (UAE), and hydrodistillation (HD) from the seeds of Perilla frutescens were analyzed by capillary GC-MS and elucidated based on the standard mass spectral data. 33, 31 and 29 kinds of volatile components were identified respectively. Relative mass fractions of the constituents were determined by area normalization method. The identified relative contents of essential oils were 97.16%, 97.38% and 96.6%, respectively. There were differences among some chemical constituents of three kinds of essential oils. But their main constituents were n-Hexadecanoic acid, (Z,Z,Z)-9,12,15-Octadecatrien-1-ol and pentyl 2-furyl ketone.