The　goal　of　an　on-line　ontology-based　question-answering　system　is　to　automatically　derive　answers　from　ontology　knowledge　bases　without　demanding　additional　information　or　intervention　from　users.　This　paper　focuses　on　the　problem　of　automatically　mapping　the　tokens　of　a　question　into　OWL　elements,　as　an　important　step　towards　the　further　construction　of　answers.　This　problem　can　be　essentially　viewed　as　that　of　question　understanding.　The　basic　ideas　underlying　our　method　can　be　stated　as　follows:　first　we　translate　the　tokens　of　a　question　as　well　as　their　syntactical　and　semantic　relations　(as　in　NLP)　into　constrained　question　variables　and　functions,　and　thereafter,　we　utilize　an　optimization-based　assigning　mechanism　to　substitute　the　question　variables　with　the　corresponding　constructs　in　OWL　knowledge　bases.　In　the　paper,　we　will　discuss　our　preliminary　studies　using　the　questions　collected　from,　and　the　knowledge　base　built　at,　the　International　WIC　Institute　(WICI).