Giardia lamblia is a widely concerned archezoan. In order to study the phylogeny of G.lamblia, ITS(1 and 2) of ribosome gene(rDNA) and 5.8 SrDNA from various Giardia strains were amplified,cloned and sequenced. A molecular phylogenetic tree was constructed with NJ method. After analyzed by DNAMAN software, 12 bases in 2 of the 10 squences were found to be substituted and 1 of the 2 had one base deletion, while the other 8 squences were quite homologous. The constructed phylogenetic tree was consistent with the phylogenic relationship reported previously. All the results show that ITS(1 and 2) and 5.8 SrRNA genes are effective genetic markers for studies of the evolution of Giardia.
