Abstract: Objective To clone and express the geneencoding lactate dehydrogenase(LDH)protein from Teania saginata and to studyits mimunological characters.Methods The gene was cloned into prokaryotic expression vector pET-28a(+)and then transformed to E.coli BL21 with IPTG induction.There after,the gene product was analyzed by SDS-PAGE and western blotting and purified by NiN-TA affinity chroma to graphy.Results The gene encodes 332 aminoacids with a theoretical molecular weight of 35.4kDa.As demonstrated by PCR,double enzymedigestion and DNA sequencing,there combinant plasmid pET-28(+)LDH was constructed successfully,and high expression of E.coli BL21 was obtained as demonstrated by SDS-PAGE assay.The recom binant prote in could be recognized by serum of patients with Taenia asiatica and Taeniarhynchus saginatus infection,indicating its mimunoreactivity.Conclusion Highly purified preparation of the protein with definite immunoreactivity was obtained through purification with affinity.