Castor seed, as non-edible energy oilseed, was used to obtain several products, such as biodiesel, ricinine, and non-toxic castor seed meal through ultrasonic-assisted two-phase extraction (UATPE), alkaline transesterification, and recrystallization. The products with higher quality could be obtained by UATPE in shorter extraction time. The optimum conditions for UATPE were as follows: the extraction time of 60 min, the corresponding temperature of 55 degrees C, the ratio of castor seed meal, petroleum ether and deionized water was 1:4:6 (mg/mL/mL). Castor oil which was obtained by UATPE was used to produce the biodiesel. And the yield of biodiesel could come up to 95.7% with the temperature of 60 degrees C, the molar ratio of methanol to oil of 7:1, the amount of the catalyst of 0.7%, and the reaction time of 60 min. Meanwhile, with the trichrolomethanol as re-extraction agent, and ethanol as the recrystallization agent, the purity and recovery of the ricinine could be got to 97.7% and 93.8%, respectively. In addition, the structural characterizations of the obtained ricinine and biodiesel were carried out by UV, FITR, ESI-MS and other analytical methods. (C) 2017 Elsevier Ltd. All rights reserved.