This study utilizes experimental analysis with window program VCTM V1.0 to investigate the thermal performance of the vapor chamber and apply to 30 Watt high-power LEDs. The thermal experiment method is derived a novel empirical formula for the effective thermal conductivity of the vapor chamber and calculated its thermal performance. Results show that the maximum effective thermal conductivity is 870 W/m degrees C from the novel empirical formula, and comparing it with the experimental value, the calculating error is no more than +/- 5%. And the LED vapor chamber-based plate works out hot-spot problem of 30 Watt high-power LEDs, successfully. (C) 2010 Elsevier Ltd. All rights reserved.