In order to solve the problems that double-phase-drive type ultrasonic motors (USMs) need to equalize the two natural frequencies for driving and that single-phase-drive type USMs either only move unidirectionally, a single-phase-drive bi-directional linear USM composed of an inclined slider and a towertype stator is presented. The inclined slider is installed with the stator which works under the symmetric vibration mode in one plane or the bending vibration mode in another plane. When the stator working mode is changed, the inclined direction of the driving-foot trajectory is changed, so the stator can move the slider bi-directionally. On the basis of analyzing the working principle and the design principles of the motor, the obliquity range of the inclined slider which can make the motor run normally is derived. Finally, a prototype is fabricated and the tests of vibration mode and mechanical characteristics are accomplished. The experimental results show that under the condition that the slider obliquity is 35° and the voltage is 500 Vp-p and the pre-pressure is 4.5N, when the motor is working under the symmetric vibration mode in one plane, the motor offers a maximal driving force of 0.5N, and the maximal velocity with no load is 79mm/s; and when the motor is working under the bending vibration mode in another plane, the motor offers a maximal driving force of 0.8 N, and the maximal velocit y with no load is 756 mm/s.