The hypocotyl of Zi No.5 and Xiubi No.2 mature seeds were used as explants. Adventitious buds were induced on optimized MS medium(20 g/L sucrose, 9 g/L agar) with 0.25 mg/L TDZ. The results showed that an average of 4.0 normal buds was produced on each explant from Zi No.5 and Xiubi No.2 and the difference in the quantities of normal buds produced from Zi No.5 and Xiubi No.2 was not obvious. The plantlets were developed from vigorous buds of the two seeds by elongating and induced rooting. The results indicated that the amounts of adventitious buds as well as the difference in the capacity of root differentiation of the two selected castor species was not obvious, which reveals that there exists no significant differences between the two selected castor genotypes in construction of in vitro regeneration system.