Robert, Here is the relevant code: =========================================== from the header file for the class being serialized... #include "boost/serialization/shared_ptr.hpp" #include "boost/serialization/nvp.hpp" #include "boost/date_time/posix_time/ptime.hpp" #include "boost/date_time/posix_time/time_serialize.hpp" . . . private: friend class boost::serialization::access; template<class Archive> void serialize(Archive& ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(WkFlo::RetractionMixin); ar & BOOST_SERIALIZATION_NVP(mNode); ar & BOOST_SERIALIZATION_NVP(mExportId); ar & BOOST_SERIALIZATION_NVP(mExportStart); }//serialize() where mNode is a shared_ptr<>, mExportedId is a string, and mExportStart is a ptime. =========================================== from the test source file... #include "boost/archive/xml_iarchive.hpp" #include "boost/archive/xml_oarchive.hpp" #include "boost/serialization/shared_ptr.hpp" #include "boost/serialization/nvp.hpp" . . . void ExportedNode_Test::serializationTest() { const char* archiveFile = "temp/Exported_Node_archive.xml"; remove(archiveFile); // remove any file with that name MockNode_ptr BasicNodeObj1(new MockNode(2312)); ExportedNode_ptr testObj_out(new ExportedNode(BasicNodeObj1, "abcd")); { // save data to archive ofstream outStream(archiveFile); boost::archive::xml_oarchive outArchive(outStream); // write class instance to archive try { outArchive << BOOST_SERIALIZATION_NVP(testObj_out); } catch (exception& ex) { cerr << "write: " << ex.what() << endl;} } // archive and stream closed when destructors are called . . . } where the outArchive << is what wrote: <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <!DOCTYPE boost_serialization> <boost_serialization signature="serialization::archive" version="3"> <testObj_out class_id="0" tracking_level="0" version="1"> <px class_id="1" tracking_level="1" version="0" object_id="_0"</boost_serialization> and threw the exception: "unrecognized XML syntax" Is this enough to go on? Merrill