Abstract: Objective To identify and classify six isolates of swine-originated Trichinella from China. Methods Five specific pairs of primers were synthesized based on DNA sequence of expansion segment V region and internal transcribed spacers （ITS1 and ITS2） of ribosomal DNA repeat from Trichinella. International reference strains of five Trichinella species ［Trichinella spiralis （T1）， T. nativa （T2）， T. britovi （T3）， T. pseudospiralis （T4） and T. nelsoni（T7）］ were used as control. Six swine Trichienlla isolates from Henan， Yunnan， Harbin， Tongjiang of Heilongjiang， Hubei and Tianjin were identified by multiplex PCR and its effecting factors of PCR amplification were observed. Results Electrophoresis results of multiplex PCR products of Trichinella larvae showed that the band （173 bp） of the six isolates was the same as T. spiralis（T1）. The specific band （173 bp） was detected by multiplex PCR through amplification from issues of single T. spiralis larva， the larvae conserved in 80% ethanol for 6 months， the larvae stored in 10% formaldehyde， in 0.05% formaldehyde， 0.2% sodium azide or 0.05% merthiotate for 2 weeks，or fresh mouse muscle with larvae. Conclusion All the six swine Trichinella isolates are identified as T. spiralis （T1） by multiplex PCR.

Key words: Trichinella, Chinese isolates, Multiplex PCR, Identification