A lamp assembly is provided, including a light source, a thermal module, a connecting member, and an adapter electrically connected to the light source. The thermal module includes a first thermal member and a second thermal member which are formed by a die casting process, wherein the light source is disposed on the second thermal member. The first and second thermal members respectively have a plurality of first and second fins which are arranged in a staggered manner. The connecting member is formed by a metal extrusion process and extends through the first thermal member to connect the second thermal member with the adapter.