A clip (10) includes a main body (20), a buckling piece (40), and a camming member (30). The main body includes a pressing part (22), a first leg (24) extending downwardly from one end of the pressing part, and a supporting portion (26) extending horizontal from an opposite end of the pressing part. The supporting portion defining a hole. The cam member located above the supporting portion which comprises a cam (32) and a handle (34) extending from the cam for rotating the cam. The buckling piece located below the supporting portion which comprises a connecting part (42) and a second leg (44) extending from the connecting part. The connecting part move up through the hole of the supporting portion to pivotally connect with the cam, and the heak sink can be secured to the electronic device by rotating the cam to a locked position from an unlocked position.