A stylus comprises a housing, a stylus body and a shaft. The housing has a receptacle defined therethrough. The stylus body assembly is slidably and non-rotatably accommodated in the receptacle of the housing, the stylus body assembly includes a threaded hole defined therethrough. The shaft rotatably passes through the housing, the shaft includes a threaded portion engaging with the threaded hole such that rotation of the shaft relative to the housing causes the stylus body assembly to slide relative to the housing to extend out or retract into the housing.