We have constructed a large scale and detailed database of lexical types in Japanese from a treebank that includes detailed linguistic information. The database helps treebank annotators and grammar developers to share precise knowledge about the grammatical status of words that constitute the treebank, allowing for consistent large-scale treebanking and grammar development. In addition, it clarifies what lexical types are needed for precise Japanese NLP on the basis of the treebank. In this paper, we report on the motivation and methodology of the database construction.