Compound verbs of the form "Verb+Verb" are known as a productive word formation type in Japanese. There are, however, few versatile databases of V+V compounds available. This paper investigates what kinds of linguistic information are expected in an adequate database of compound verbs. First, a list of compound verbs that are gathered from several dictionaries and other resources is explained. Then the kinds of information included in the existing databases of compound verbs are discussed with a view to clarifying the essential semantic, syntactic, and morphological information from two viewpoints: one is the viewpoint of linguistic research on the word-formation and lexical semantics of V+V compounds, and the other is the viewpoint of the information provided by Japanese dictionaries for simplex verbs. Finally, part of the database of compound verbs under construction is shown by way of illustration.