Foam metal phase change composite materials and systems play a crucial role in the heat (cold) storage system. The interfacial thermal conductance between different foam metals and phase change materials under different phases is an important factor to affect the heat (cold) storage process of the heat (cold) storage system. In this paper, the interfacial thermal conductance between the three metals (copper, aluminum and nickel) and two phase change materials (paraffin and erythritol) in solid and liquid is measured by time-domain thermoreflectanctechnique. The experiments suggest that regardless of the types (paraffin or erythritol) and phases (solid or liquid) of phase change materials, the interfacial thermal conductance results preserve the same trend that copper < nickel < aluminum. By performing a series of molecular dynamics simulations and phonon-level analyses, the mechanisms for the above trend are identified to be the dominant contribution of lattice vibration in z direction and mismatching degrees of metal/phase change material interfaces. The interfacial thermal conductance of metals/paraffin are bigger than metals/erythritol in the same conditions. Compared with solid state, two kinds of phase change materials in liquid state show bigger interfacial thermal conductance for all kinds of metals.