An apparatus for displaying sub page content includes a display unit, a storage unit, and a processing unit. The apparatus communicates with a network server. The processing unit obtains a webpage from the network server and one or more sub pages linked to the webpage. The display unit displays a first window for displaying label of each sub page designating a type which is binding with each sub page. The processing unit controls the display unit to display a second window for displaying the sub page content of the label displayed on the first window which is determined to be selected according to whether operation position of user's operation performed on the first window is on the area of the label of sub page displayed. A related method is also provided.