Abstract: Objective To investigate the expressions of tyrosine kinase receptor EphA2 and ligand ephrinA1 in human astrocytoma and their correlations with prognosis. Methods Expression levels of EphA2 and ephrinA1 were detected by immunohistochemical assay in 55 cases of surgically resected human astrocytoma tissues and 15 cases of normal brain tissues. CD105-stained microvessel density (MVD) in microvascular endothelial cells were also measured. Results Expressions of EphA2(51/55) and CD105-MVD (34.26±12.61) in human astrocytomas were signifi cantly higher than those in normal brain tissues(P<0.01). With the increased pathology grade of human astrocytomas, ephrinA1 expression was decreased; CD105-MVD was significantly positively correlated with EphA2 expression (r=0.713, P<0.01), and significantly negatively correlated with ephrinA1 expression (r=－0. 772, P<0.01). EphA2 was signifi cantly negatively correlated with ephrinA1 expression (r=－0.912, P<0.01). EphA2, CD105-MVD and ephrinA1 were all important risk factors for astrocytomas prognosis. Overall and progression-free survival of patients with positive EphA2 and CD105-MVD and negative ephrinA1 was signifi cantly shorter than those with all positive EphA2, CD105-MVD and ephrinA1, all negative EphA2, CD105-MVD and ephrinA1, or negative EphA2 and CD105-MVD and positive ephrinA1. Conclusion EphA2 and CD105-MVD are specifically up-regulated and ligand ephrinA1 is specifi cally down-regulated in astrocytomas and may be closely involved in the poor prognosis. EphA2 and ephrinA1 could be the new targets for diagnosis, therapeutic and prognosis evaluation of human brain astrocytomas.