An active stylus includes a pen body defining an accommodation chamber and a through hole unit, a control device mounted in the accommodation chamber and including a circuit board capable of outputting a signal to a touch control device of a touch screen being touched by the active stylus and elastic conductive members electrically connected to the circuit board and exposed to the outside of the through hole unit, and a rotating barrel rotatably mounted on the pen body around the through hole unit and including control zones movable with the rotating barrel relative to the pen body to change the contact condition between the elastic conductive members and the pen body for causing the circuit board to output one of a series of control signals to the touch control device in executing a corresponding operating function.