Abstract: Objective To investigate the expression of brain derived neurotrophic factor（BDNF）in retinoblastoma（Rb）tissues and its clinical significance. Methods The pathological-diagnosed Rb tissues（n=37）with complete clinical data were obtained from April 2008 to August 2015. Normal retinal tissues（n=12）were collected as control from traumatic removed eyes. QPCR and immunohistochemistry were applied to detect the expression of BDNF in the above tissues. The relationship between the expression of BDNF and clinicopathological parameters of Rb（age，sex，lateral aspect，clinical stage，pathological differentiation and optic nerve invasion）was analyzed. Results BDNF was highly expressed in 89.2％（33／37） Rb tissues，and mRNA level was significantly higher than that of normal retina（P＜0.01）. The percentage of BDNF positive cells in Rb tissues was（36.78±14.13）％，higher than that in normal retinal tissues（5.35±1.92）％，and the difference was statistically significant （P＜0.01）. The expression of BDNF in Rb tissues was independent of age，sex，lateral aspect and optic nerve infiltration，but was related to clinical stage and histological differentiation. The proportion of BDNF positive cells was significantly higher in stage Ⅲ and Ⅳ／Ⅴ tissues compared with that in stageⅠ／Ⅱ tissues（P＜0.01），and significantly higher in undifferentiated Rb tissues than in differentiated tissues（P＜0.01）. Conclusion The expression of BDNF is elevated in Rb tissues，and is correlated with clinical stage and pathological differentiation of Rb，which may be used to judge the malignant degree of Rb.