Rechargeable　batteries　have　attracted　significant　attention　in　recent　years　because　of　aggravate　environment　problems.　Lithium-ion　batteries　play　an　important　role　in　our　daily　life　and　extensively　used　in　portable　electronic　devices　as　well　as　hybrid　electric　vehicles.　However,　the　uneven　distribution　and　limitation　of　lithium　resources　have　gradually　aroused　people＇s　anxiety　on　lithium-ion　battery　sustainability.　Sodium-ion　batteries　have　been　studied　by　many　groups　recently　and　potentially　used　as　one　of　the　next-generation　rechargeable　batteries　due　to　the　earth　abundance　and　cost-effectiveness　of　sodium　resources.　The　key　to　commercialize　the　promising　sodium-ion　rechargeable　batteries　mainly　lies　on　the　development　of　advanced　electrode　materials.　Transition　metal　oxides　are　one　of　the　oldest　and　most　important　electrode　materials　for　sodium-ion　batteries,　and　have　been　studies　by　many　researchers　for　about　30　years,　especially　in　recent　five　years.　Here,　with　a　main　line　of　crystalline　structure　design　for　transition　metal　oxides,　the　whole　research　progress　on　transition　metal　oxides　used　for　sodium-ion　batteries　has　been　reviewed,　some　important　research　results　in　recent　five　years　are　emphatically　introduced,　and　the　perspective　on　novel　electrode　materials　development　is　also　discussed.　©　2016