The information about eBook cannot be added automatically to library catalog because the eBook Service Provider does not provide enough eBook metadata. Therefore, this paper was developed the eBook library's metadata in order to maintain the compatibility and interoperability among various metadata standard. In trying to accomplish this, we have comparatively analyzed the eBook service provider's metadata, KS X 6100 metadata, Dublin Core, MARC, and TEI Header, and extracted common metadata elements from them. We defined these common metadata elements as a core element and added other elements that uniquely describe eBook characteristics as a detailed and additional elements for eBook metadata.