bZIP ( basic leucine zipper ), as one of the most abundant members of the plant transcription factor family, is mainly involved in plant growth and development, stress response, and hormone signal transduction regulation. In this study, based on the transcriptome data of castor, a bZIP gene that was significantly up-regulated under low-temperature stress was cloned and named RcbZIP11(GenBank No. OQ506490). The coding region sequence of the RcbZIP11 gene was 492 bp in length, which deduced 163 amino acids. It was predicted to be a hydrophilic protein with a conserved bZIP _ plant _ GBF1 domain. Multiple sequence alignment showed that RcbZIP11 protein was relatively conservative during evolution. Phylogenetic tree analysis showed that RcbZIP11 had the closest relationship with JcbZIP11 protein. Subcellular localization showed that the RcbZIP11 protein was localized in the nucleus. The promoter sequence of the RcbZIP11 was successfully cloned. The prediction results showed that the region had light response elements, stress response elements, and hormone induction elements. RcbZIP11 gene was expressed in different tissues ( true leaves, cotyledons, stems, and roots ) of castor, and the relative expression level was the highest in cotyledons. The relative expression levels of RcbZIP11 in roots and leaves under stress ( drought, salt, low temperature, and ABA ) were higher than 0 h, indicating that the RcbZIP11 gene was actively involved in the abiotic stress response of castor. In summary, this study lays a foundation for further exploring the function of the RcbZIP11 gene in the growth process of castor under stress conditions.