Objective To verify that combined detection of P53 protein and tumor markers in serum was better than any single marker detection on auxiliary diagnosis of the distant metastasis of digestive malignant neoplasm.Methods There were 55 post-operation patients with digestive malignant neoplasm diagnosed by pathology,all the cases were divided into metastasis group(19 cases with distant metastasis) and non-metastasis group(36 cases without distant metastasis),in addition to 14 healthy volunteers.We detected P53 protein and CEA,CA19-9,CA242,CA72-4 in serum by ELISA.Results The P53 level in serum in metastasis group were higher than that in non-metastasis group(P0.05),which in metastasis group and non-metastasis group were both higher than that in healthy control group(P0.05).P53,CA19-9,CA72-4 were risk factors of the distant metastasis of digestive malignant neoplasm.Applying the three to diagnose the distant metastasis of digestive malignant neoplasm,the sensitivities were respectively 84.2%,73.7%,47.4%,the specificities were respectively 100%,77.8%,97.2%.For parallel test of P53 and CA19-9,the sensitivity was 100.0%,the specificity was 61.1%.Conclusion P53 is a valuable single marker for auxiliary diagnosis of the distant metastasis of digestive malignant neoplasm.When P53 protein in serum is higher than 0.4086U/ml,it can be used to auxiliaryly positively diagnose the distant metastasis of digestive malignant neoplasm.When P53 and CA19-9 are both negative,it can be used to auxiliaryly deny the distant metastasis of digestive malignant neoplasm.