To clone, express the procalcitonin (PCT) and prepare its polyclonal antibody.We designed 10 DNA primers according to the encoding sequence of human PCT gene from GenBank, amplified PCT gene by PCR and constructed the recombinant vector pGEX-KG-PCT. Then the fusion protein, PCT-GST, was expressed in E.coli and purified by affinity chromatography. The corresponding polyclonal antibody was produced in the New Zealand white rabbits immunized with the fusion protein, and its biological activity was detected by Western blotting. The specificity and titer of the polyclonal antibody was identified by agar gel immunodiffusion test.We successfully obtained the full-length PCT gene and expressed the fusion PCT-GST in E.coli. SDS-PAGE showed that relative molecular mass (Mr;) was about 36 000. Agar gel immunodiffusion test revealed that the prepared polyclonal antibody could specially recognized PCT and its titer was 1:4.The PCT is successfully cloned, expressed and purified. The high specific polyclonal antibody of PCT is prepared.