Aim To investigate the effect of protein kinase C inhibitor on expression of intercellular adhesion molecule-1 protein and mRNA in smoking rats.Methods The expression of intercellular adhesion molecule-1 protein and mRNA were abserved by immunohistochemistry and in situ hybrizition.18 non-infarcted rats were randomly divided into three groups including 6 non-smoking rats,6 no medicine treated smoking rats and 6 protein kinase C inhibitor treated smoking rats.48 infarcted rats were randomly divided into two groups including 24 no medicine treated rats and 24 protein kinase C inhibitor treated rats.2 hours,6 hours,12 hours or 24 hours after infarction the medicine were given,6 rats in each time points.Results Compared with no medicine groups,the expression of intercellular adhesion molecule-1 and intercellular adhesion molecule-1 mRNA were decreased with corresponding indentical time points in protein kinase C inhibitor groups,which showed statistical difference(p<0.05).Conclusions Protein kinase C inhibitor could reduce the expression of intercellular adhesion molecule-1 and intercellular adhesion molecule-1 mRNA in smoking rats cerebrovascularendothelial cells,the medicine were given more early,more effect will be produced.