In this work a thermodynamic performance analysis is carried out for a combined cycle consisted of an organic Rankine cycle (ORC) and a LNG cycle. The combined system uses a low grade waste heat in the form of sensible energy and the LNG cold energy is used for power generation as well as for heat sink. The effects of the key parameters of th system such as turbine inlet pressure, condensation temperature and source temperature on the characteristics of system are throughly investigated. The simulation results show that the thermodynamic performance of the combined system can be significantly improved compared to the normal ORC which is not using the LNG cold energy.