A receptacle assembly that receives a back light assembly and a display unit of a liquid crystal display device is disclosed. The receptacle assembly for receiving the back light assembly comprises a first receptacle module and a second receptacle module engaged with the rear surface of the first receptacle module to support the first receptacle module. The first receptacle module and the second receptacle module are formed of plastic and metal respectively. Therefore, the distortion that can be generated by the exterior impact and the vibration and the deflection due to the heat can be prevented. Further, the productivity is improved by simplifying the engaging structure of the receptacle assembly, and the size stability is improved.