The stent graft system in accordance with the present invention has a trunk, a left subclavian tube, a left common carotid tube and a brachiocephalic tube. The trunk is tubular and expandable and has a descending end, an ascending end, a left subclavian mount, a left common carotid mount and a brachiocephalic mount, for receiving the aforementioned branch tubes that are elastic and self-expandable for respectively connecting the left subclavian artery, the left common carotid artery and the brachiocephalic artery to the trunk. With the above-described structure, the present invention allows fast determination of a suitable trunk and branch tubes for a patient and allows a medical institute to prepare compatible branch tubes and trunks for a composite stent graft system instead of numerous stent grafts of various combinations of differently sized tubular bodies and branches, wherein the former requires significantly less warehousing cost than the latter.
