Hello Dung,

In order to remove the border of active tab item of the UltraTabControl you will need to use Draw filter. To use Draw Filter you have to create your class implementing IUIElementDrawFilter interface. In your draw filter class you have to catch TabItemUIElement on BeforeDrawFocus draw phase and to stop drawing it. More about Draw Filters you can find by following the next link http://help.infragistics.com/Doc/WinForms/current/CLR4.0/?page=Win_Draw_Filter.html

Please find attached a sample solution implementing above described steps.

Please let me know if this is what you are looking for or if I am missing something.

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