Thermal problem is still a bottleneck to limit the stability, reliability, and lifetime of High power light emitting diodes (LEDs). More effective thermal design LED packages with low thermal resistance is critical to improve the performance of LEDs. In this paper we present thermal analysis of type of thermal performances of the plastic package and metal package of LEDs. The analysis was made by transient thermal measurement. The two kind of ceramic packages under investigation employ same configuration of GaN-based chip, but they have different structure, size and distribution thermal vias. Two design of LED packages resulted in significantly different thermal performance. Thermal properties, described as thermal resistance, of two package design, were compared and evaluated. It was demonstrated that the junction temperature decrease with effective contact in the LED packages.