A damping sliding rail is described. The damping sliding rail has an elastic member, a buffer member, a buffer stud, a fixing stud, and a switch. The elastic member provides an opening force to open apart a first casing from a second casing. The buffer member provides a damping force to slow down the opening speed between the first casing and the second casing. When the first casing and the second casing are closed together, the fixing stud compresses the elastic member to store an elastic energy for opening apart the first casing from the second casing. When the switch is pressed to open the first casing from the second casing, the fixing stud is released by an indentation of the switch and the buffer stud presses on the buffer member to reduce the opening speed.