So there is no way to get at the XML within the XML with basex?
The XQuery 3.0 parse-xml() function should do what you want:
let $doc := <description><![CDATA[<ul><li>復興廣播電台...</li><li>台北市士...</li><li>丙</li></ul>]]></description> let $xml := string($doc) return parse-xml($xml)