Porous medium is playing an important role in technological advances nowadays. They exist everywhere in nature and were widely used in lots of engineering projects due to their huge internal surface area and ultrafine pore size. These properties allow them to achieve good performances in heat and mass transfer. So, the regenerator of Stirling Engine uses porous medium as the matrix to get higher heat transfer efficiency. In this study, the regenerator of a 55W Stirling engine was calculated using the 1D numerical model to find the most efficient porous media from kinds of options with different structures and different parameters.