The objective of this study was to investigate the protective effect of the excitatory amino acid receptor antagonist, α-melanocyte stimulating hormone, on the retina. Twenty-four Sprague Dawley (SD) rats were randomly divided into normal control group, glutamate induced injury group and α-melanocyte stimulating hormone pretreatment group each with 8 rats, 16 eyes in each group. The content of neurotransmitter amino acids and the survival rate, apoptosis rate and mitochondrial membrane potential of the retinal nerve cells were compared between the three groups. According to our results the contents of free glutamate, γ-aminobutyric acid, taurine, glycine and aspartate were all higher in the induced injury group than in the normal control group, which were significantly lower in the intervention group than in the induced injury group, though higher than the normal control group, showing statistically significant difference between the three groups (P<0.05). Absorbance value of retinal nerve cells was significantly higher in the normal control group than in the induced injury group and the intervention group, which was significantly higher in the intervention group than in the induced injury group, showing statistically significant difference between the three groups (P<0.05). Retinal ganglion cell apoptosis rate was significantly higher in the induced injury group than in the normal control group, which was significantly lower in the intervention group than in the induced injury group, though higher than the normal control group, showing statistically significant difference between the three groups (P<0.05). The mitochondrial membrane potential of retinal nerve cell was obviously lower in the induced injury group than in the normal control group, which was obviously higher in the intervention group than in the induced injury group, though still lower than the normal control group, showing statistically significant difference between the three groups (P<0.05). It is concluded that excitatory amino acid receptor antagonist, α-melanocyte stimulating hormone, can effectively antagonize glutamate-induced apoptosis of retinal nerve cells, whose mechanism may be related to the enhancement of mitochondrial transmembrane potential.