Abstract: With the automatic shedding mechanism according to this invention, the warping conditions are inputted by using the program setting unit 151. When it arrives at the predetermined position, the warping drum stops rotating. The closed reed 38 is operated to from lease, into which the lease rods 88 enter so as to maintain the lease and move upward to keep the lease. Next, the lease tape driving mechanism 94 is operated to have its movable unit 98 advance, so that the lease tapes T will be let off onto the warping drum 12 to the predetermined amount. Then the lease tapes go between the lease to maintain them. The above operation will be repeated for every band for the number of times according to the total number of the warping yarns and warping width. Therefore the shedding procedure will be continuously performed without cutting the warping yarns for each band. After the warping procedure, the lease cords are passed through the holes on the heddle hooks at the leading ends of the lease tapes.