A study on the multiple primary malignant tumor of digestive tract (MPMTDT) was made in the period of 1984-1988 in our hospital. Twenty five cases are reported in this paper. All of them were examined by X-ray, endoscopy, and proved to be MPMTDT by surgery and pathological examination. Twenty three cases were double primary tumors and 2 cases triple primary malignant tumors. The characteristic X-ray feature of the site of predilection and manifestation in primordial period of MPMTDT are described in this paper. These criteria are important for the early detection and selection of treatment of the tumors.