The ultrasonic assistance extraction technology of the prickly ash oil from prickly ash seeds was studied, and the effects of extraction medium, temperature, time and rate of liquid to solid was discussed. Meanwhile, chemical compositions of prickly ash oil extarcted from its seeds and shell were analyzed by gas chromatography-mass spectrometry (GC-MS) respectively. The results showed that the extraction rate of prickly ash oil is 7.8% by using 95% ethanol as extractant with a ratio ethanol/ash (v/w) of 3:1 (mL/g) and extracting at 60 °C for 90 min. Heat treatment of prickly ash, however, led to a lower rate under the corresponding conditions. The chemical compositions of both oils are very different with alkenes from seeds and with carboxylic acids together with its esters from shell.