Objective To study the expression and distribution of postsynaptic density protein-93 (PSD-93) after spinal cord injury (SCI). Methods With improved Allen’s method, acute rats SCI models were established. Realtime PCR and Western blotting were used to detect the changes of PSD-93 mRNA and protein expression after SCI. The changes of PSD-93 localization after injury were investigated by immunofluorescence double staining. Results The expression of PSD-93 mRNA had a gradually decrease trend after SCI. The minimal mRNA was present at 3days; whereas the protein levels upregulated significantly and peaked at 1day after injury. Immunofluorescence double staining indictated that PSD-93 was highly expressed on the activated microglias and astrocytes except that it colocalized with nNOS in the impaired spinal cord.Conclusion The time course of PSD-93 and its mRNA is vary significantly after SCI, and colocalized with nNOS and activated glias. These results indicate that PSD-93 may participate in the f