Abstract: Tubulin genes are highly conserved and are often used as internal reference genes in the study of relative expression of target genes. In this study, in order to express the fusion protein of beta-Tubulin1 gene（RcTUBβ1） from castoroil plant（Ricinus communis L.）, the recombinant prokaryotic expression vector pET32 a（+）-RcTUBβ1 was constructed and the expression conditions were optimized. Open Reading Frame（ORF） sequence of RcTUBβ1（GenBank Accession: XM＿002509734.3） was amplified from the female flowers of castor, through RT-PCR using a pair of specific primers containing restriction endonucleases recognition sites of Bam HⅠand XhoⅠ. ORF sequence of RcTUBβ1 was ligated into pET32 a（+） by double enzyme digestion to construct the recombinant expression vector. This recombinant expression vector was then transformed into E. coli strain BL21（DE3） to induce the expression of fusion protein His-RcTUBβ1. The effects of induction temperature, induction time and concentration of IPTG on induced expression were investigated. The results showed that the obtained RcTUBβ1 ORF sequence was consistent with the sequence in Genbank, with a length of 1 341 bp with no code mutation. The recombinant expression vector was successfully constructed and named as pET32 a（ +）-RcTUBβ1. A fusion protein with a molecular weight of approximately 68 kD, inducted by IPTG, was successfully expressed in E.coli BL21. The optimal expression conditions for the fusion protein were induction temperature 28 ℃, induction time 7 h and concentration of IPTG 0.5 mmol/L. The fusion protein existed mainly in forms of inclusion body.The results provided a foundation for purifing the fusion protein and preparing polyclonal antibody, which were the necessary materials for further research of the immunohistochemical distribution and spatio-temporal expression pattern of RcTUBβ1.