An elliptical trainer includes a base frame, a swing unit axially mounted at the base frame, a pedal unit axially mounted at the swing unit, a damping unit for providing a damping resistance to the swing unit, a guiding unit and an elastic device unit. The guiding unit includes a pair of cranks respectively connected to the damping unit and a pair of guide brackets respectively pivotally connected to the cranks. Each guide bracket includes a guide wheel slidably coupled to the base frame and a bearing member for supporting one respective stepping bar. The elastic potential energy of the elastic device set constantly keeps the rear end portions of the stepping bars in proximity to the base frame and the stepping bars in abutment against the bearing members. The matching arrangement of the guiding unit and the base frame achieves high operating smoothness and supporting stability.