ISpatialReferenceFactory3 spatialReferenceFactory = new SpatialReferenceEnvironmentClass(); //geometryDefEdit.SpatialReference_2 = spatialReferenceFactory.CreateGeographicCoordinateSystem((int)esriSRGeoCSType.esriSRGeoCS_Beijing1954); geometryDefEdit.SpatialReference_2 = spatialReferenceFactory.CreateProjectedCoordinateSystem((int)esriSRProjCS4Type.esriSRProjCS_Xian1980_3_Degree_GK_Zone_39);