Abstract: Objective: To investigate the effects of heparanase inhibitor laminarin sulfate on the expression of heparanase relevance gene uPA, VEGF in the tumor carried by nude mice. Methods: After EC9706 cells were disposed by four concentrations laminarin sulfate (0.2μg/ml, 0.4μg/ml, 0.6μg/ml, 0.8μg/ml) for 24 hours, they were injected into nude mice, the protein expression of heparanase relevance gene uPA, VEGF in the tumor carried by nude mice were observed by using immunohistochemistry SP method. Results: The expression of uPA and VEGF proteins in transplanted tumor was inhibited by four concentration inhibitor laminarin sulfate, especially 0.6μg/ml, the inhibitory effect on VEGF was stronger compared to that on uPA, but there was no significant difference between them (P>0.05). There was a significant difference between control group and experimental group (P<0.05). Conclusion: Observation shows that laminarin sulfate can inhibit the expression of uPA and VEGF protein in tumors carried by nude mice, indicating that laminarin sulfate is an effective inhibitor for invasion and metastasis of tumors and can provided a new clue for preventing invasion and metastasis of tumors clinically.