During the taxonomical investigations of Coleoptera (family: Meloidae) of the Arak County, in spring and summer 2010, 15 species of blister beetles belonging to the two subfamily (Nemognathinae and Meloinae), three tribes (Mylabrini, Lyttini and Nemognathini) and six genus (Hycleus, Mylabris, Alosimus, Calydus, Teratolytta and Nemognatha) were collected and identified. In this study the geographical distribution and identification key of the collected species of blister beetles were considered. This is the first time that Calydus ornaticollis species from Arak and Teratolytta flavipes species from Iran was reported. Morphological characters such as mesosternum, antennae, pronotum, and male reproductive organ were the main identification character that was used.