The new liquefaction cycle of natural gas has been designed and simulated in this paper. Conventional LNG cycles using MR (Mixed Refrigerant) are usually composed with several Joule-Thomson expansion processes. The new concept of natural gas liquefaction cycle is to replace the last stage J-T expansion with turbine expander. The turbine expander is to extract pressure exergy at the lowest temperature expansion process. This regenerated energy is provided to the compressor which consumes energy to pressurize refrigerants. The composition of the mixed refrigerant is investigated in this study. Methane, propane and nitrogen are selected as the MR (Mixed Refrigerant) and their composition for the new process is traced with Aspen HYSYS software. LNG heat exchangers are analyzed for the new process. Heating and cooling curves in heat exchangers are also analyzed.