Abstract: In order to investigate the composition and content of hawthorn flavonoids, a gradient high performance liquid chromatography ( HPLC) was developed for the detection of rutin, hyperoside and quercetin from hawthorn.Acetonitrile and 0.4% phosphate solvent was used as mobile phase, external standard method was adopted for quantification of three flavonoid yield, extraction technique of the three flavonoid yield was optimized and the mathematical model was established.The results showed that the sequence of factors was as follows: liquid to solid ratio > volume fraction of ethanol > extracting time > ultrasonic power, the optimal condition for ultrasound assisted extraction condition was that volume fraction of ethanol 90%, liquid to solid ratio 25.5mL /g, ultrasonic power 600W, extracting time 24.9min, under the optimal extraction conditions, the flavonoid yield was 0.0363%.In this test, it was found that rutin, hperoside ande quercetin were the main flavonoids in hawthorn, which could be extract efficiently by ultrasound assisted method.