PURPOSE: To simplify the structure by connecting a tie rod interlocked by a pitman arm on power steering side and a tie rod interlocking a knuckle arm protruding frontward of steering wheel on one side to the upper and lower surfaces of a knuckled arm protruding frontward of steering wheel on the other side, respectively.

CONSTITUTION: On lateral both end parts of a front accelerator housing 10 for tractor, final cases 26 for rotating steering wheels 1, 6 installed to a front wheel shaft 25 are provided in such a manner as to be capable of steering around king pines 27, and a knuckle arm 2, 7 having the middle part curved in crank form to form a vertical difference in level is protruded on each final case 26. A power steering 3 interlocked by a steering shaft 16 is mounted on the front part of a vehicle body 9, a pitman arm 4 is provided on an arm shaft 28 protruding downward from the power steering 3, and the top end of the pitman arm 4 is connected to the base part lower side surface of the knuckle arm 2 by a tie rod 5. The top end upper side surfaces of the left and right knuckle arms 2, 7 are connected to each other by a tie rod 8.