AIM: To clone and express CML66 cDNA and to prepare rabbit anti-CML66 antibody. METHODS: cDNA isolated from the testis using RT-PCR was cloned into pGEMT. After sequencing, the cDNA was inserted into prokaryotic expression vector pET32b(+). The recombinant vector was transformed into BL-21(DE3) through electroporation. 6xHis-tagged CML66 expression was then induced by IPTG. The protein was purified through Ni(2+) affinity chromatography column and characterized by SDS-PAGE and Western blot. The purified protein was injected into rabbits to prepare polyclonal antibody. RESULTS: The cloned cDNA sequence was identical with that previously reported. The target protein was successfully purified. And rabbit's anti-serum with high titer was obtained. CONCLUSION: We have cloned CML66 successfully, expressed and purified the protein in E.coli.Furthermore,rabbit polyclonal antibody has been obtained.