Objective: To provide experimental evidences what can be developed and utilizated, and for establishing the medicinal quality standard of Helianthus annuus' s root. Methods: GC - MS. Results: 33 effective components have detected. Sesquiterpene lac- tones, Steroidal, Coumarin are main contents. Conclusion: The components of essential oil from Helianthus annuus' s root, with the changing of structure types and spatial configuration, should present a wide ...