18S rRNA gene, encoded small subunit ribosomal RNA and 1800bp, was 80% in organism and regarded as highly conserved molecules in course of evolution, so 18S rRNA gene was the important marker for organism taxonomy and system evolution. In this study, we cloned and analyzed 18S rRNA gene sequences of five Trichinella isolates. The result is meaningful in identifying and classifying the different Trichinella isolates. The ES protein of Trichinella was the Excretory-Secretory (ES) products of the alive worms. ...