Objective To investigate the effect of the hypertonic sodium chloride hydroxyethyl starch 40 injection on focal cerebral ischemia/reperfusion injury (I/RI) in mice. Methods Thirty KM mice were divided into three groups (n=10) randomly:hypertonic hydroxyethyl starch 40 sodium chloride group (group HSH), hydroxyethyl starch 130/0.4 group (group HES), control group (group control). At onset of ischemic insult, different agents were injected via the tail vein instantly. Mice in group HSH received 4 ml/kg of hypertonic hydroxyethyl starch 40 sodium chloride injection. Mice in group HES received 4 ml/kg of hydroxyethyl starch 130/0.4 sodium chloride injection. Mice in group control received 4 ml/kg of 0.9％ physiological saline injection. Neurological behavioral testing was performed at 12, 24 and 72 h after ischemia, respectively. TTC staining was performed at 24 h after ischemia,and the percentage of infarction area was calculated. Toluidine blue staining was performed at 72 h after ischemia and surviving neurons in the penumbra were counted. Results Neurological scoring at 12, 24 h and 72 h after ischemia: HSH group 10.0±2.0,11.4±1.8, 10.4±1.8; HES group 12.8±1.8, 10.2±1.9, 10.6±2.7; Control group 12.0±2.1, 10.2±2.4, 10.0±2.5. The percentage of infarct area at 24 h after ischemia: HSH group (34.0±7.8)％; HES group (38.8±2.9)％; Control group (35.6±6.5)％. The density of surviving neurons in the penumbra at 72 h after ischemia: HSH group (264±57)/mm2; HES group (302±49)/mm2; Control group (288±69)/mm2. There were no difference in neurological deficit score, percentage of infarct areas and density of surviving neurons in the penumbra among three groups, respectively(P＞0.05). Conclusion Hypertonic hydroxyethyl starch 40 sodium chloride injection has no effect on focal cerebral I/RI in mice.