A heat pipe heat sink which is possible to frozen start up at the lower than -20℃ by using a VCHP was designed, manufactured and tested. The VCHP uses water and nitrogen gas as the working fluid and non-condensable gas. The test results showed that the VCHP heat sink started up successfully at the range of -20 to -30℃ of the ambient temperature and 1000 to 2600W of the heat flow rate. The thermal resistance of the VCHP heat sink decreased as increased the heat flow rate and the ambient temperature since the active zone of VCHP increased.