Objective: Simulated the process of heat wave and compared Apo E-/ - mice’ sICAM-1 levels, body weight and rectal temperature，explore the effect of heat wave on sICAM-1. In order to further investigate the impact of heat wave on cardiovascular disease. Methods: Eighteen Apo E Knockout Mice were divided into the heat wave group，BH4 and control group. The body weight and rectal temperature of every mouse were measured every day. Used of meteorological environment simulation box to simulate the process of heat wave, and determinates sICAM-1 of Apo E Knockout Mice after heat wave, measured by enzyme linked immunosorbent assay (ELISA). Results：The sICAM-1 and rectal temperature of Apo E Knockout Mice in group of heat wave were much higher than that in BH4 and control group. There were statistically significance among control group BH4 and heat wave group (P<0.05). Conclusion: The influence of heat wave on sICAM-1 of Apo E Knockout Mice indeed exists. We can deduce that the patients who have vascular dysfunction can be influent by the process of heat wave. What’s more, BH4 may reduce the hazards caused by heat wave weather.