Abstract: A cordless widow shade includes at least an upper track, a lower track, a shade assembly and an automatic winding means. The upper track has a holding trough to hold the automatic winding means and wire directing sets close to two sides thereof to direct a first lift cord and a second lift cord of the shade assembly. The automatic winding means has a retaining set to hinge a transmission assembly. The transmission assembly includes a first transmission wheel, a second transmission wheel and an elastic element. The elastic element is an S-shaped elastic reed with two ends coupling on the first and second transmission wheels. Through rotation of the automatic winding means, retraction and extension of the cordless window shade can be controlled to facilitate operation.