COX-2 is a multifunctional neuronal modulator, however, its many functions are still unclear and need to be investigated further. Normal adult rat COX-2 cDNA was amplified by PCR from rat brain cDNA library. Sequencing result showed that the cloned gene was identical with that having reported. Expression vectors of whole COX-2 coding gene and its partial coding sequence in carboxyl terminal were respectively constructed by PCR and gene recombination techniques and were transformed into E.coliDH5α, for IPTG-induced expression. The results showed that there was no COX-2 fusion proteins expressed in E.coliDH5α which were transformed with expression vectors of whole COX-2 coding gene, whereas in E.coliDH5α which were transformed with expression vectors of partial coding gene in carboxyl terminal, COX-2 fusion protein was expressed in the form of inclusion body. A protein band of M_r being 44 000 appeared on SDS-PAGE gel. The protein expressed by carboxyl terminal coding sequence had a high purity after denaturation, refolding and purification. New Zealand rabbits were immunized with COX-2 fusion proteins to prepare a polyclonal antibody against COX-2. The COX-2 antiserum was obtained and characterized by ELISA, Western blot, immunohistochemistry and immunocytochemistry. Results showed that the antibody has high titer, affinity and specificity. The studies provide a favorable tool for further functional study of COX-2 in future.