Abstract: A power-free descending device for emergent escape from a building which comprises a frame having a hook engaged on the top thereof for hanging on fixed objects and having an opening on central bottom thereof, two partition boards vertically positioned in the frame to divide the frame into three sections, a principal shaft with a central spiral part for the winding of ropes, several friction plates separately positioned underneath the principal shaft and respectively supported by a spring, two plates with one hole in each plate for coupling with one end of the principal shaft to position the shaft, and a rope winding on the central spiral part of the shaft with both ends stretching from the opening of the frame. When escaping from a high building, people grasp one end of the rope and the shaft rolls intermittently and slowly under the influence of the spring and the resistance of friction plates. The descending speed is therefore slow and the people can safely escape from the building.