Abstract: Objective 　To investigate the correlation between the expression of vascular endothelial growth factor (V E GF) and it s receptor KD R and angiogenesis in human pituitary adenomas. Methods 　V E GF and KD R were detected in 58 cases pituitary adenomas by immunohistochemical S-P technique. Microvessel density was determined by immunostaining for factor CD₃₄ related antigen. Results 　VEGF was expressed in 54 cases (93. 1 %), mainly located at cytoplasm or the membrance of pituitary adenomas cells ;KD R was expressed in 47 cases (81. 0 %), it was located in the vascular endothelial cell of pituitary adenomas tissues and in the cytoplasm or the membrane of the pituitary adenomas cell. Both VEGF expression and KD R were well correlated with the invasiveness. The microvascular density (MVD) was significantly greater in VEGF and KD R higher expression groups than in lower group s ( P < 0. 01) . Conclusion V E GF promotes angiogenesis synergism KDR by paracrining or autocining in pituitary adenomas, and take part in tumor invasiveness.