A core technology that may realize the Semantic Web is Ontology. The OWL (Web Ontology Language) has been positioned as a standard language. It requires technical expertise to directly represent the domain knowledge in OWL. Based on our experience of analyzing the fundamental relationships of concepts in e-catalog domain, we have developed a visual product information modeler called PROMOD. The modeling editor makes it possible to automatically generate the OWL codes for the given product information. We employ an Extended Entity-Relationship for conceptual modeling, enriched with modeling elements specialized for the product domain. In this paper, we present our translation schemes from EER model to OWL codes, and how to design and implement the modeling editor. We also provide a scenario to demonstrate the usage of the editor in practice.