The invention relates to a device for controlling a winding speed of a winding roll for a screen or shade which adjusts resilience of a torsion spring to increase or decrease the winding speed of the winding roll, preventing mechanical friction with improved operational capability. In the device, a worm wheel is integrally formed in a shaft supporting part receiving an end of the winding shaft, and is rotatably in contact with a stopper plate enclosing a side of an outer shell. Also, an adjustment member having an end penetrating through a front portion of the outer shell is disposed horizontally adjacent to the worm wheel and perpendicular to the winding shaft. Further, the worm wheel is in mesh with a worm integrally formed in a middle portion of the adjustment member.