Objective: To analyze the main chemical constituents of the essential oil in flower of H. manihot Method: The essential oils were extracted from flower of Hibiscus manihot L.. by s microwave-assisted extraction (MAE) and steam distillation (SD).The amount of the components from the essential oil were determined by normalization method. The components separated were identified by GC-MS. Result: There were 34 components from Tooan sinensis Roem. by MAE that composed of about 99.35% of the total essential oil were separated and identified; There were 37 components from Tooan sinensis Roem. by SD that composed of about 94.81% of the total essential oil were separated and identified. Conclusion: The present study provide scientific bases for exploitation of flower of H. manihot in reason.