A cancer invasiveness diagnosis system includes an endoscope; a microtomography probe which is introduced into a body cavity together with the endoscope, the microtomography probe emitting a low-coherence light on a target tissue in which a target tumor is present to obtain an optical interference signal; a determination portion which is configured to obtain a tomography image of the target tissue including the target tumor and a blood flow velocity information in a blood vessel in the tomography image based on the optical interference signal, wherein the determination portion is configured to determine the cancer invasiveness of the target tumor based on the tomography image and the blood flow velocity information.