The present invention is intended to clarify the relationship between PAR-2 and cerebral infarction and thereby provide an efficient method of preventing and treating cerebral infarction, as well as a pharmaceutical composition therefore. Namely, the present invention relates to a method of preventing and treating cerebral infarction by activating PAR-2 and/or promoting expression of PAR-2 gene. The present invention further relates to a pharmaceutical composition for preventing and treating cerebral infarction, comprising one, or two or more of the active ingredients selected from the group consisting of a PAR-2 activator and/or a PAR-2 gene expression promoter; as well as a pharmaceutically acceptable carrier. It further relates to a method of screening an active ingredient for preventing and treating cerebral infarction using as an indicator the PAR-2 activation promoted by a test substance.