After spinal cord injury (SCI), the reactive glial cells secrete increased amount of proteoglycans (PGs) during the wound healing process. Overproduced proteoglycans may form astroglial scars, which blocks axonal regeneration and causes the impaired neuronal function repair. Chondroitin sulfate proteoglycans (CSPGs), a type of the protepglycans, are known to inhibit axonal regeneration. In contrast, heparin sulfate proteoglycans (HSPGs) may promote neurite outgrowth. In recent years, a hydrolysis enzyme, hyaluronidases-4, has been considered to be the an endogenous enzyme acting at the initial step in the catabolism of chondroitin sulfate. However, the expression and distribution of hyaluronidase-4 (Hyal4) after CNS injury is unclear. In this study, we followed the expressions of various types of proteoglycans and their catabolic enzymese in a rat model with spinal cord hemisection injury for 6 weeks. Six-week-old Sprague-Dawley (SD) rats were randomly divided into 2 groups including control (laminectomy at T9) and spinal cord injury (laminectomy and hemisection at T9). Serum and cerebrospinal fluid samples were collected every week. The expressions of the proteoglycans and the CSPG catabolic enzyme, Hyal-4 were analyzed by dot blot analyses. Immunohistochemistry was carried out for the proteoglycans and the enzumes in spinal cord tissue. The altered expressions of the proteoglycans and Hyal-4 were correlated with the severity of SCI based on the BBB score and the motor function.. The altered expressions of PGs and hyaluronidae-4 maybe used as biomarkers to evaluate the severety and the functional recovery after SCI.