A system for detecting function of an intestinal barrier in a subject is provided, which includes: a contrast agent for being administered directly to an intestinal lumen of the subject, allowing a detecting device to detect in vivo or in vitro the signal indication produced by the contrast agent in the tested targets such as abdominal organs or a blood sample; and a determining device for determining intensity of the signal indication produced by the contrast agent in the tested targets after the administration of the contrast agent so as for the intensity of the signal indication after the administration of the contrast agent to indicate damage of the intestinal barrier in the subject. The present invention also provides a method of detecting function of the intestinal barrier in a subject by using the system of the present invention.