The　documents　selection　related　brain　information　based　on　the　data-brain　ontology　not　only　has　an　important　significance　in　the　promotion　of　data-brain　ontology,　but　also　lays　the　foundation　for　knowledge　integration.　However,　traditional　research　of　documents　selection　focuses　on　the　concept,　and　cannot　meet　the　requirement　of　the　systematic　Brain　Informatics　study.　This　paper　analyzes　the　characteristics　of　source　knowledge　firstly　with　concepts,　attributes　and　relations.　Then,　we　calculate　the　weight　of　documents　by　using　the　improved　method　of　VSM.　Finally,　the　experiments　using　real　documents　associated　with　brain　science　are　given　and　calculating　the　weight　of　each　document　achieves　a　better　effect　of　ranking　selection.　©　2014　Springer　International　Publishing.