Titanium　dioxide　(TiO2),　as　an　important　semiconductor　metal　oxide,　has　been　widely　investigated　in　the　field　of　photocatalysis.　The　properties　of　TiO2,　including　its　light　absorption,　charge　transport　and　surface　adsorption,　are　closely　related　to　its　defect　disorder,　which　in　turn　plays　a　significant　role　in　the　photocatalytic　performance　of　TiO　2.　Among　all　the　defects　identified　in　TiO2,　oxygen　vacancy　is　one　of　the　most　important　and　is　supposed　to　be　the　prevalent　defect　in　many　metal　oxides,　which　has　been　widely　investigated　both　by　theoretical　calculations　and　experimental　characterizations.　Here,　we　give　a　short　review　on　the　existing　strategies　for　the　synthesis　of　defective　TiO2　with　oxygen　vacancies,　and　the　defect　related　properties　of　TiO2　including　structural,　electronic,　optical,　dissociative　adsorption　and　reductive　properties,　which　are　intimately　related　to　the　photocatalytic　performance　of　TiO2.　In　particular,　photocatalytic　applications　with　regard　to　defective　TiO2　are　outlined.　In　addition,　we　offer　some　perspectives　on　the　challenge　and　new　direction　for　future　research　in　this　field.　We　hope　that　this　tutorial　minireview　would　provide　some　useful　contribution　to　the　future　design　and　fabrication　of　defective　semiconductor-based　nanomaterials　for　diverse　photocatalytic　applications.　©　2013　The　Royal　Society　of　Chemistry.