To provide a boot for a constant velocity joint capable of preventing damage caused by contacting with a clamp and heightening the bulkhead.

A bulkhead 26 for hindering a bellow part 14 from interfering with a first clamp 15 when a driven shaft held swingably in a case 17 constituting a constant velocity joint 16 and a space 27 for hindering a clamp calking jig J for caulking a first clamp 15 from interfering with the bulkhead 26 when the clamp 15 is to be caulked are provided between a first fixation part and the bellow part 14. As a result, the driven shaft swings largely, and when the bellow part 14 is compressed large, there is no risk that the bellow part 14 touch directly the first clamp 15 because bulkhead 26 exists between them 14 and 15. This allows preventing the bellow part 14 from being damaged by interference with the first clamp 15.