A spring winding type window shade includes a headrail providing a first fastening device, a curtain having a second fastening device located at one end thereof and fastened to the first fastening device of the headrail, scroll springs longitudinally and tightly bonded to the curtain with respective one ends thereof fastened to the second fastening device of the curtain, and a clamp for clamping the respective opposite ends of the curtain and scroll springs remote from the headrail so that the curtain and the scroll springs can be received in an accommodation space in the clamp in a rolled up condition. When pressing a press portion of the clamp, the clamp is opened, allowing the curtain to be rolled up or extended out with the scroll springs. When release the applied pressure from the press portion, the clamp automatically clamps the curtain and the scroll springs again.