BACKGROUND: Trauma can damage the spinal cord or cauda equina to different degrees. Previous studies have verified that traditional Chinese medicine has effects on spinal cord injury via a variety of pathways. OBJECTIVE: To observe changes in hemorheology and inflammatory factors in spinal cord injury rats following treatment with the Chinese medicine Jisuikang, to verify the dose-dependent effect of Jisuikang, and to compare its effects with the effects of prednisone. DESIGN, TIME AND SETTING: A randomized study was performed at the Research Institute of Orthopedics, and Experimental Center of First Clinical Medical College, Nanjing University of Traditional Chinese Medicine, China from September 2007 to March 2008. MATERIALS: Jisuikang powdered extract, composed of milkvetch root (30 g), Chinese angelica (12 g), red peony root (12 g), earthworm (10 g), szechwan lovage rhizome (10 g), peach seed (10 g) and safflower (10 g), was provided by the Experimental Center, First Clinical Medical College, Nanjing University of Traditional Chinese medicine. Each gram of powdered extract was equivalent to 6.47 g crude drug. METHODS: A total of 72 Sprague Dawley rats were randomly assigned into 6 groups (n = 12). Rat models of spinal cord injury were established using the occlusion method. Rats in the model group were treated with distilled water. Rats in the 25 g/kg, 12.5 g/kg, and 6.25 g/kg Jisuikang groups were given 25 g/kg, 12.5 g/kg, or 6.25 g/kg Jisuikang by gavage, for 14 days. Rats in the prednisone group received 0.06 g/kg prednisone by gavage, for 7 days. Rats in the normal group were given the same volume of distilled water. The volume of administration was 15 mL/kg.MAIN OUTCOME MEASURES: Rat serum interleukin-10, tumor necrosis factor-α (TNF-α), nitric oxide, nitric oxide synthase levels, malondialdehyde content, superoxide dismutase activity and whole blood viscosity were measured in each group. Spinal cord around the site of the model was collected. Half the spinal cord was used for histopathologic examination. The other half was used for measurement of nitric oxide and NOS levels, malondialdehyde contents, and superoxide dismutase activity. RESULTS: Superoxide dismutase activity was higher in the 25 g/kg Jisuikang group than in the model group. Malondialdehyde contents, nitric oxide and NOS levels were lower in the 25 g/kg and 12.5 g/kg Jisuikang groups compared with the model group. Whole blood viscosity was lower in the 25 g/kg and 12.5 g/kg Jisuikang groups compared with the model group (P < 0.05-0.01). Serum TNF-α content was lower in each Jisuikang group compared with the model group (P < 0.05-0.01). Serum interleukin-10 levels were greater in the prednisone group and each Jisuikang group compared with the model group (P < 0.01). Mild hemorrhage and necrosis in the rat spinal cord, and unclear neural cell swelling were seen in the 25 g/kg Jisuikang group. Severe hemorrhage and necrosis in the rat spinal cord, and distinct neural cell swelling were seen in the 12.5 g/kg Jisuikang group. Edema in the white matter was found in the 6.25 g/kg Jisuikang group. Pathological changes in the prednisone group were identical to the 25 g/kg and 12.5 g/kg Jisuikang groups. CONCLUSION: Jisuikang inhibits nitric oxide synthase expression, reduces nitric oxide and TNF-α levels, decreases malondialdehyde content, increases interleukin-10 levels and superoxide dismutase activity, improves indices of hemorheology, and prevents secondary changes in spinal cord injury, resulting in relieving pathological changes in spinal cord tissue. The outcome was significant in the 25 g/kg Jisuikang group compared with the 12.5 g/kg Jisuikang group.