A shifter is fixed on a handle of a bicycle and connected with a rear speed changer of a cable and contains: a body, a first bar, and a speed changing mechanism, the body including the first bar, a chamber to receive the speed changing mechanism, and two tabs, and each tab including a first hole, and the body including a first aperture arranged on a top end thereof and communicating with the chamber to insert the cable into the chamber via the first aperture so as to connect with a first seat, the body including a first retaining ring, the chamber including a first positioning pillar, an axial shaft, a second aperture, and a first returning spring, the first positioning pillar being provided to fix a first fixing piece in the chamber, and the axial shaft being used to axially position a first hook in the chamber.