Abstract: ObjectiveTo study the difference of gdh gene seqences between Strepto coccus suis type 2 isolated from human and pig and the reference sequence in order to detect Strepto coccus suis type 2.MethodsApair of primers was designed with the aid of NCB Iand literatures,and then the amied gene was amplified with PCR.After purified,the amplified products were cloned to pMD 19-Tvector and sequenced.ResultsThe gdh gene sequences of Strep to coccus suis type 2 isolated from human and pig were so conserved that just two bases were different.They were found to be identical except one base difference with reference sequence analyzed by DNA star program.The gdh gene sequences of Strepto coccus suis type 2 isolated from human is T but the reference is Cat the position 828.The gdh gene sequences of Strep to coccus suis type 2 isolated from pig is Cbut the reference is Tat the position 662.ConclusionThe gdh gene sequences of Streptoco ccus suis type 2 isolated from human and pig are highly conservative.