ObjectiveTo study the factors associated with meningioma peritumoral edema.MethodsPeritumoral edema of 18 patients was assessed on a semi - quantitative form from preoperative radiography. All the patients' clinical information( tumor size, tumor envelope damage, brain surface vein compression, pathological type), malignancy of tumor tissue, vascular endothelial growth factor(VEGF), immuno-histo-chemisty stain were studied to find out the correlation with peritumoral edema. Results There was no correlation between tumor size, pathological type and brain vein compression with peritumoral edema。 Tumor envelope damage and VEGF immunoreactivity were strongly associated with peritumoral edema. ConclusionThese data suggest that meningioma peritumoral edema may bea result of tumor cell producing VEGF in combination with tumor envelope damage, which lead to the damage of normal blood brain barrier and the enterance of edema-causing chemical factor.