The male genitalia of eleven species of Alydidae, Rhopalidae and Coreidae are illustrated and described. In Alydidae, the aedeagus is of tube form. In Rhopalidae, it either separates into two (right and left) plates with the inner surface of each plate having notches or reduces to only one (left) plate. In Coreidae, it only has left plate which spirals twice at base; and the ejaculatory duct runs through the longitudinal notch on its inner surface. The reasons of rejudgment on the aedeagus are offered.