Morphologies of male genitalia of Elateridae (Insecta: Coleoptera) were examined comprehensively by using scanning electron microscopy (SEM). Aedeagal ultrastructures of 65 species were investigated in detail. New morphological structures including small pustules on the apical part of median lobe, small pits with short spine on median lobe and parameres and spines and teeth of inner sac of median lobe were observed for the first time. The long and short bristles of male genitalia were examined comprehensively. Systematic value of these structures are evaluated within examined genera and subfamilies by using a cluster analysis. These morphological structures are heterogeneous within the subfamilies. Consequently, results of cluster analysis exhibit that the observed structures can not be accepted as taxonomical characters for differentiating subfamilies with the exception of the diagnosis of some genera.