Abstract: Primary extract the active elements from the root,stem and foliage of Artemisia annua L with petroleum ether (30~60℃), petroleum ether (60~90℃), ethanol, acetone and water were carried out in laboratory, then further separation of active elements was detected by column chromatography, and then the separated elements′acaricidal activitie was measured against Tetranychus cinnabarinus. The results indicated that acetone extract was the most effective to T. cinnabarinus in different solvent extracts of the root, stem and foliage of A. annua L. However the foliage acetone extract was the most effective against T. cinnabarinus, of which the corrected mortality was 98.95% within 48h(5mg/ml). In the 13 main separated groups, the eleventh and twelfth had the best activities. The corrected mortality against T. cinnabarinus was 99.30% and 99.29% respectively within 48h at the concentration of 5mg/ml. The toxicity regression linear analysis of these two groups against T. cinnabarinus were 0.3683 and 0.1586 mg/ml, respectively.