In this paper, ionic liquid-aqueous solution ultrasonic-assisted extraction (ILUAE) has been successfully applied in extracting camptothecin and 10-hydroxycamptothecin from Camptotheca acuminata samara. The ionic liquids with different cations and anions have been investigated, and 0.75 M 1-octyl-3-methylimidazolium bromide was selected as solvent. In addition, the ultrasonic parameters including ultrasonic power, time for ultrasonic treatment and solid-liquid ratio have been optimized by Response Surface Methodology. Compared with conventional solvent extraction, ILUAE exhibited higher efficiency (camptothecin increased by 13.96% and 10-hydroxycamptothecin increased by 24.04%, respectively) and shorter extraction time (decreased from 6 h to 1.75 h for extracting three times), which indicated that ILUAE was an efficient, rapid and simple sample preparation technique. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.