A connector for stretch straps of a chair is mounted on the chair to hold and stretch a stretch strap with an opposite connector mounted on the chair and has a receiving recess formed inside the connector and a connecting slot formed through the top of the connector and communicating with the receiving recess. One end of the stretch strap extends through the connecting slot to be held by a binder in the receiving recesses. A bottom of the stretch strap is propped out by a top edge of the connecting slot so that a top of the stretch strap is protrudent relative to the top of the connector and a sharp edge formed between the top and the front end of the connector. Thus, a user's body is prevented from contacting with the rigid top and the sharp edge of the connector to comfortably sit on the chair.