Abstract: The use of ultrasonic-assisted process(UAP) was investigated for solvent extraction of azadirachtin from neem seed under different operating conditions.Influences of ultrasonic power,solvent,ratio of material to liquid and ultrasonic treatment time on the yield of azadirachtin were studied.Optimal ultrasonic-assisted extraction conditions were:ratio of material to liquid 1:2(w/v) and ultrasonic power 200 W for 13.3 g seed powder.It was found that (extraction) yield of azadirachtin and ultrasonic time were different with different solvents(methanol as solvent,ultrasonic time 15 min,yield of azadirachtin 0.378 6%;ethanol as solvent,ultrasonic time 20 min,yield of azadirachtin (0.365 8%);ethyl acetate as solvent,ultrasonic time 10 min,yield of azadirachtin 0.246 2%).Content of azadirachtin in (extract was) estimated with HPLC technique.Results showed that UAP technique not only enhances the extraction yield of azadirachtin from neem seed but also has the advantage of high efficiency,compared to that of conventional solvent extraction method.