A tube bender is provided. The rotatable member is pivoted to a pivot portion of a base and defines an inner space, and the rotatable member has a gear portion, a first arched groove and a holding portion. The gear portion archedly extends around the pivot portion. The first arched groove archedly extends around the pivot portion on an outer circumferential surface of the rotatable member, and the holding portion has a holding recess. The abutting assembly includes an abutting chunk assembled to the base and an arm member connected with the abutting chunk. A gear assembly includes a driving portion pivoted to the arm member and a gear connected and synchronously-movable with the driving portion. The gear engaged with the gear portion in the inner space.