Abstract: Restriction enzyme digestion of total genomic DNA of two chromosome forms of Paragonimus westermani showed the presence of homologous highly repeated DNA in both diploid and triploid forms. Southern blotting analysis provided further evidence that the distribution, of restriction enzyme sites (with 3 enzymes) on repetitive sequence of DNA of both forms were similar. However, with PstⅠ, Ddel, HaeⅢ and HpaⅡ, their polymorphism revealed differences which were also found in each form tested separately with the hybridization technique.The present study, at the molecular level, supports the previously reported biological and biochemical results that they might be considered as different isolates or forms.It is suggested that PstⅠ, DdeⅠ, HaeⅢ and HpaⅡdigestion pattern might be useful to distinguish the diploid from the triploid forms of Paragonimus westermani.