A mounting device for mounting a first element onto a second element includes a plurality of fastening elements. Each of the fastening elements includes a connecting member defining a clasping groove therein, and a guiding portion adjacent to the clasping groove. A ring-shaped clipping member snaps in the clasping groove of the connecting member after moving over the guiding portion to be expanded. A fixing member is coupled to the connecting member for sandwiching the first element and the second element therebetween. A resilient member adapts for being sandwiched between the connecting member and the first element to provide resilient force to urge the first element toward the second element.