A base of tablet computer includes a housing, a moving member, and an interface assembly. The housing has a trench, a first sidewall, and a second sidewall connected to the first sidewall. The first sidewall forms a portion of the trench and has a first opening. The second sidewall forms another portion of the trench and has a second opening. The moving member is configured to move relative to the housing to selectively enter or exit the trench via the first opening. The interface assembly protrudes to a side of the second sidewall adjacent to the trench via the second opening, and is configured to rotate relative to the second opening based on an axis. The interface assembly is operatively connected to the moving member, so as to be rotated by the moving member while the moving member is moved relative to the housing.