To assess mechanical properties of tissues, strain must be generated in an object. However, a single radiation force is not effective because it mainly generates translational motion when the object is much harder than the surrounding medium. In the present study, two cyclic radiation forces are simultaneously applied to a muscle phantom from two opposite horizontal directions so that the object is cyclically compressed in the horizontal direction. By the horizontal compression, the object is expanded vertically based on its incompressibility. The resultant vertical displacement is measured using another ultrasoundpulse. The displacement of several micrometers in amplitude was measured by the ultrasonic phased-tracking method. Increase in thickness inside the object in the vertical direction was observed at the time of increasing acoustic radiation forces. Suchchanges in thickness corresponded to vertical expansion due to horizontal compression and show that the proposed method successfully generated strains inside the object.