The present research work deals with theTaxonomic Relevance of Internal male genitalia in subfamily Arctiinae (Arctiinae:Arctiidae:Lepidoptera) collected from North-East India. The collection-cum-survey tours to various North-Eastern States viz. Assam, Arunachal Pradesh, Manipur, Mizorum, Nagaland, and Sikkim, yielded a rich harvest of 1670 adult representatives of subfamily Arctiinae. From this collected lot, as many as 39 species under this subfamily has been identified with the help of literature and confirmed by comparison. All these species have been dissected and preserved in the field during collection tours. The illustrations of the internal male genitalic features have been drawn with the help of trisimplex projector.The internal male genitalic attributes of all the identified species have been studied in detail and can be incorporated in the detailed diagnosis of the species.