Based on the thermoelectric separation concept, metalized AlN ceramic blocks of high thermal conductivity were embedded into FR4 materials of relatively low thermal conductivity for the preparation of ceramicembedded substrates for LED heat dissipation management employing lamination technologies. Secondly, LED lamps were mounted on the aforementioned substrates to form LED modules, the junction temperature of which were tested using junction temperature tester and temperature control table in terms of different AlN sizes and different LED powers. Additionally, the heat dissipation performances of the aforementioned substrates were studied on the base of junction temperature test results. The result showed that when the LED powers were constant, both the spread thermal resistances and onedimensional thermal resistances of the ceramicembedded substrates decreased as the AlN block sizes increased, thus led to decreased overall thermal resistances.