An efficient plant regeneration protocol was established for castor bean(Ricinus communis L.), in which 0.3 mg L~(–1) thidiazuron(TDZ) induced shoot clusters and increased the number of adventitious shoots from hypocotyl tissue. Our results showed that treatment under dark conditions significantly promoted the average number of shoots per explant to 37.36±4.54(with a 6-d treatment). Modified 1/2 Murashige and Skoog(MS) basal medium supplemented with 440 mg L~(–1) Ca~(2+), 0.2 mg L~(–1) gibberellic acid and 0.1 mg L~(–1) TDZ significantly increased shoot elongation rates and lowered vitrification rates. Furthermore, 1/2 MS media supplemented with 0.2 mg L~(–1) 1-naphthaleneacetic acid induced a higher rooting rate compared with other culture conditions. An efficient plant regeneration protocol was established for castor bean (Ricinus communis L.), in which 0.3 mg L -1 thidiazuron (TDZ) induced shoot clusters and increased the number of adventitious shoots from hypocotyl tissue. Our results showed that treatment Under dark conditions significantly promoted the average number of shoots per explant to 37.36 ± 4.54 with a 6-d treatment. Modified 1/2 Murashige and Skoog (MS) basal medium supplemented with 440 mg L -1 Ca ~ (- 2+), 0.2 mg L -1 gibberellic acid and 0.1 mg L -1 TDZ under the conditions of increased shoot shoot rates and under vitrification rates. ) 1-naphthaleneacetic acid induced a higher rooting rate compared with other culture conditions.