The aim of this study was to observe the location of paired immunoglobulin-like receptor B (PirB) in the retina and to evaluate the expressive varieties of PirB in the retina of mice after optic nerve injury. In situ hybridization was used to observe the location of PirB mRNA in the retina of mice. Western blotting was used to analyze the levels of PirB protein in retina 7 days after optic nerve crush. Expression of PirB was located in the retinal ganglion cells of mice. The level of PirB protein increased significantly in the retina after optic nerve crush compared to the control group. PirB plays an important role in the inhibition of axonal regeneration after optic nerve injury. We conclude that the inhibition of PirB expression may enhance axonal regeneration after optic nerve traumas.