To provide an axle mounting structure capable of preventing occurrence of abnormal noise, reducing the number of components, and reducing the man-hour in a mounting work.
The axle mounting structure comprises a laminate 21 with rubber sheets 22 and metal sheets 23 being alternately laminated on each other, a lower mounting plate which has a first mounting hole 24a formed in its center, and is laminated on a lower side of the laminate and mounted on an axle 26, a rebound stopper bolt 28 which is abutted on a head 28a around the first mounting hole 24a of the lower mounting plate 24 with a screw part 28b passed through the laminate 21 and its upper portion being passed through a second mounting hole 17b formed in a leaf spring 17, and a nut 29 screwed to an upper portion of a screw part. A semi-spherical lower recess 24c is formed in the lower mounting plate; a lower semi-spherical surface 28c tightly fitted to the lower recess is formed on the head part; an upper semi-spherical surface 29a facing the second mounting hole is formed on the nut; and an upper recess 17c tightly fitted to the upper semi-spherical surface 29a is formed in the leaf spring or an auxiliary leaf spring 31 laminated on the leaf spring.