The aim of this Master Thesis was the determination of the thermal boundary conductance (TBC) of various metal matrix composites (MMC). The thermal boundary conductance is an important property of MMCs regarding their use as so called heat-sink materials, as it limits the maximum achievable thermal conductivity, a key feature of modern heat-sink materials. In the course of this Master Thesis SiC- and Al2O3-powders of various sizes were infiltrated by Al, Ag, AgSi, Zn and Bi using gas pressure infiltration (GPI). The TBC of the various MMCs was determined by measuring the thermal conductivity of composites with different inclusion sizes. By applying the DEM-model (differential effective medium approach) to determine the effective thermal conductivity and plotting the inverse effective thermal conductivity against the inverse particle radius of a given metal/ceramic-combination (invers method) the TBC can be obtained. Parameters, which influence the thermal boundary conductance of MMCs, where also studied in this work. Most important is a strong connection of the metal matrix and the inclusion phase, more specifically the production of a dense composite. The ratio of the Debye temperature of the metal matrix and the ceramic inclusion also plays a major role, especially if the goal is to reach or determine the highest possible TBC. The TBC of certain MMCs can also be influenced by heat treatment.