Because of the development of LED technology, products due to high output and compact, thematerial with high thermal conductivity has been developed. Now that heat radiating part of the LEDlamp is currently used for die casting of aluminum. The development of aluminum with excellent thermalconductivity is required. In this study, we measured the thermal properties and compared them while weproduced the alloy by changing the component of die casting aluminum. From this study, the thermalconductivity and thermal resistance of the developed alloy were superior to die casting aluminum.