Objective To inquive into 125I seeds interstitial brachytherapy on the malignant tumor in digestive tract.Methods Analyse retrospectively 104 patients with different malignant tumor of stage Ⅱ and stage Ⅲ in digestive tract.All patients received radical resection.125I intraoperative implantation to tumor bed and regional lymph nodes.Complete bland count was determined during postoperative 5-7 days and immuoassay,and X-ray film were taken to observe the distribution of 125I seeds,understand tumor recurs or shifie the situation.Results All patients are followed up a case by regular,Don't have death.Among them one of interstitial Lou happens 8 patients WBC count decreased to 3×109/L within one week and rose to 4×109/L after suit the remedy to the case.Immunity ralve was below normal survive patient apper serious complication that lead to the fact because plant into 125I seeds follow up a case by regular visits to.while being other.Conclusion 125I seeds interstitial beraehytherapy for the malignant tumor of stage Ⅱ and stage Ⅲ in digestive tract is simple,safe and effective especially good application prospects in basic wint.