Objective:To explore the mechanism of the anti-tumor effect of Aidi Injection.Methods:Human lung squamous cell carcinoma xenografts were transplanted into 30 nude mice.Mice were randomLy divided into 3 groups:The Aidi Injection group received Aidi Injection(12 g·kg-1)

0.2 mL

peritoneal injection) every day for 20 days

the chemotherapy group received DDP(1 mg·kg-1)

0.2 mL peritoneal injection) every day for 7 days

and the control group received normal sodium(0.2 mL peritoneal injection) every day for 20 days.They were sacrificed afterwards and their tumors were processed for histological examination.The weights of the tumors were measured

the vessel density of the tumor and the expression of VEGF in tumors were detected using immunohistochemical method.Results:The cancer inhibition rates of Aidi Injection and DDP are 45.6% and 78.3% accordingly.In the Aidi Injection group

the vessel density of the tumor and the expression of VEGF in tumors decreased.In the DDP group

the vessel density of the tumor decreased

while the expression of VEGF in tumors increased.Conclusion: Aidi Injection can inhibit the expression of VEGF in tumor and decrease the vessel density of the tumor.