Abstract: In order to find out the most suitable treatment temperature and time for establishing a rat model of cold - induced vasogenic brain edema, three temperatures (- 60℃、-80℃ and -196℃) and four time (1、2、3、4 minutes) were used. The brass cup, filled with acetone,at the temperature of -60℃、-80℃ and -196℃ was put directly on one side of the rat bony skull resoectuvekt. The results of microscopic and electromicroscopic examinantions revealed that frost at -196℃ for 1 minute, can induce rat brain edema obviously and easily with low mortality.