Abstract: Based on the XML data streaming transformation technology,a streaming transformationmethod is proposed for transforming GML to GeoOWL.Firstly,an element mapping transformationmodel is built by analyzing the mapping between GML elements and GeoOWL elements,then it is de-scribed using STX,finally the method is implemented using streaming transformation technology.Ex-periments show that our method is accurate,efficient and less memory is consumed,thus suitable forlarge GML file transformation.