Abstract: The contents of laminin(LN)in serum were measured by radioimmunoassay in patients with gastric cancer before and after resection of the tumor. It was showed that thecontent of LN in cancer group was significantly higher than that in control group (P0.05),and the content in advanced stage group was much higher than that in early stagegroup (P0.05). After resection of the tumor the content of LN was decreased significantly, especially in radical resection group (P0.05). This implies that the content ofserum LN is closely related to the tumor invasion and metastases,and the assay of LN inserum may be useful to the diagnosis of gastric cancer.