The aims of the research was to study the occurance of strongyloidiasis and fascioliasis in Ba wean deer in correlation with gastrointestine helminthes infection on ruminant cattle in Bawean Island.Research subject was of 240 faecal sample of Bawen deer and ruminant cattle at the rainy season and dry season from Bawean Island. The obtained data of observation and laboratory examination was analysed by statistical method of chi square test.The result described that the similarity on their morphology and size of both Strongyloides sp. and Fasciola sp. egg in Bawean deer and the ruminant cattle were found inside the area reserve. That was occured because of grazing in the same pasture, water source, and had asimilarity of anatomy and taxonomy between deer and cattle. The differences of fascioliasis and strongyloidiasis were affected by the population and geographical condition, respectively. The prevalence of gastrointestine helminthes in Bawean deer and ruminant cattle were higher during the rainy season than in its dry season with P<0,05