I try to compile the first.cpp example of boost program_options library I use the command g++ first.cpp -lboost_program_options-mt. It fails when linking. But I also try use the same command to compile simple_ls.cpp of filesystem, boost_back_inserter_example.cpp of iostream, days_alive.cpp of date_time(The library link is also different). It compiles and works as expected. I use depends.exe of VS.Net 2003 to prove the exe is depended on the dll file. The error of program_options is as below Info: resolving vtable for boost::program_options::variables_mapby linking to __imp___ZTVN5boost15program_options13variables_mapE (auto-import) Info: resolving vtable for boost::program_options::value_semantic_codecvt_helper<char>by linking to __imp___ZTVN5boost15program_options29value_semantic_codecvt_helperIcEE (auto-import) Info: resolving boost::program_options::arg by linking to __imp___ZN5boost15program_options3argE (auto-import) Info: resolving vtable for boost::program_options::validation_errorby linking to __imp___ZTVN5boost15program_options16validation_errorE (auto-import) C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cckbcaaa.o(.text$_ZN5boost15program_optio ns13variables_mapD1Ev[boost::program_options::variables_map::~variables_map( )]+0x3a):first.cpp: variable 'vtable for boost::program_options::variables_map' can't be auto-imported. Please read the documentation for ld's --enable-auto-import for details. C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cckbcaaa.o(.text$_ZN5boost15program_optio ns29value_semantic_codecvt_helperIcED2Ev[boost::program_options::value_seman tic_codecvt_helper<char>::~value_semantic_codecvt_helper()]+0xb):first.cpp: variable 'vtable for boost::program_options::value_semantic_codecvt_helper<char>' can't be auto-imported. Please read the documentation for ld's --enable-auto-import for details. C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cckbcaaa.o(.text$_ZN5boost15program_optio ns29value_semantic_codecvt_helperIcEC2Ev[boost::program_options::value_seman tic_codecvt_helper<char>::value_semantic_codecvt_helper()]+0x16):first.cpp: variable 'vtable for boost::program_options::value_semantic_codecvt_helper<char>' can't be auto-imported. Please read the documentation for ld's --enable-auto-import for details. C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cckbcaaa.o(.text$_ZN5boost15program_optio ns16validation_errorD2Ev[boost::program_options::validation_error::~validati on_error()]+0x3a):first.cpp: variable 'vtable for boost::program_options::validation_error' can't be auto-imported. Please read the documentation for ld's --enable-auto-import for details. C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cckbcaaa.o(.text$_ZN5boost15program_optio ns16validation_errorD1Ev[boost::program_options::validation_error::~validati on_error()]+0x3a):first.cpp: variable 'vtable for boost::program_options::validation_error' can't be auto-imported. Please read the documentation for ld's --enable-auto-import for details. C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cckbcaaa.o(.text$_ZN5boost15program_optio ns16validation_errorC1ERKSs[boost::program_options::validation_error::valida tion_error(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)]+0x53):first.cpp: variable 'vtable for boost::program_options::validation_error' can't be auto-imported. Please read the documentation for ld's --enable-auto-import for details. C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cckbcaaa.o(.text$_ZN5boost15program_optio ns16validation_errorC2ERKS1_[boost::program_options::validation_error::valid ation_error(boost::program_options::validation_error const&)]+0x53):first.cpp: variable 'vtable for boost::program_options::validation_error' can't be auto-imported. Please read the documentation for ld's --enable-auto-import for details. collect2: ld returned 1 exit status I want to know how to link the dynamic library of program_options