Objective: Use heparin during cardiac arrest(CA) in rabbits and observe the serum intercellular adhesion molecule-1(ICAM-1) and hippocampal S100β protein expressions after cardiopulmonary resuscitation(CPR). Methods: Thirty-two New Zealand rabbits were randomly divided into, Group Ⅰ,control group; Group Ⅱ, saline group; Group Ⅲ, heparin group. Each animal underwent continuous hemodynamic monitoring including mean arterial pressure(MBP), heart rate(HR), and the end-tidal carbon dioxide partial pressure(Pet CO2). Twenty-four hours after resuscitation, serum and hippocampal neurons were collected from all animals. Enzyme linked immunosorbent assay was used to detect serum ICAM-1 and immunohistochemistry to detect the S100β protein in hippocampal neurons.According to the rate of positive cells, each hippocampal specimen was categorized into four expression levels. Results: The differences in the serum ICAM-1 concentration in the three groups were statistically significant. The expression of S100β protein in the hippocampus showed eight cases in group Ⅰ at level 1 and none in groups Ⅱ and Ⅲ. There was 1 case in group Ⅱ and 7 cases in group Ⅲ at level 2; five cases in group Ⅱ and 2 cases in group Ⅲ at level 3; 2 cases in group Ⅱ and 1 case in group Ⅲ at level 4. The expression strength of S100β protein in the three groups differed significantly(P < 0.05). Conclusions: Heparin therapy can reduce the expression of serum ICAM-1 and S100βprotein in hippocampal neurons during CPR. It is possible that heparin can have a positive effect on brain protection during CPR. Objective: Use of heparin during cardiac arrest (CA) in rabbits and observe the serum intercellular adhesion molecule-1 (ICAM-1) and hippocampal S100β protein expressions after cardiopulmonary resuscitation (CPR). Methods: Thirty-two New Zealand rabbits were randomly divided into Group II, saline group; Group III, heparin group. Each animal underwent continuous hemodynamic monitoring including mean arterial pressure (MBP), heart rate (HR), and the end-tidal carbon dioxide partial pressure CO2). Twenty-four hours after resuscitation, serum and hippocampal neurons were collected from all animals. Enzyme linked immunosorbent assay was used to detect serum ICAM-1 and immunohistochemistry to detect the S100β protein in hippocampal neurons. Accredited to the rate of positive cells , each hippocampal specimen was categorized into four expression levels. Results: The differences in the serum ICAM-1 concentration in the three groups were significant significant. The expr ession of S100β protein in the hippocampus showed eight cases in group Ⅰ at level 1 and none in groups Ⅱ and Ⅲ. There was 1 case in group Ⅱ and 7 cases in group Ⅲ at level 2; five cases in group Ⅱ and 2 cases in group Ⅲ at level 3; 2 cases in group Ⅱ and 1 case in group Ⅲ at level 4. The expression strength of S100β protein in the three groups differed significantly (P <0.05). Conclusions: Heparin therapy can reduce the expression of serum ICAM -1 and S100βprotein in hippocampal neurons during CPR. It is possible that heparin can have a positive effect on brain protection during CPR.