Abstract: Objective To identify histidine triad prote in(HTP)gene in Streptococcus suis sero type 2(S.suis 2),and to study its an tigenicity.Methods Bioinformatics was adopted to analyze the genome database of the Chinese stra in 05ZYH 33 of S.suis 2.Prmiers were designed for HTP,and the target DNA fragment was amplified using the genomic template o f 05ZYH33.HTP gene was subsequently inserted into pEASY-T1 vector and subcloned into expression vector pET28a.The plasmid was confirmed by direc tDNA sequencing and tran sformed in to E.coli BL21(DE3)competent cells to express recom binant HTP.The recom binant prote in was purified with His-Resin.We stern blot was used to identify the antigenicity of recom binant HTP.Results The 2.7kbhtp sequence was amplified from the genome of 05ZYH 33,and the recombinant HTP can be produced in E.coli.A 110 kD prote in can be observed in SDS-PAGE,and Western blot experiment demon strated that the prote in shared strong specific antigenicity.Conclusion HTP can function as a novel antigen of S.suis 2,and may play pivotal roles in the severe infection of S.suis 2.