In this study, the change in the cutting forces generated during machining of MgO-reinforced metal matrixed composites (MMC) was determined and the relationship was specified between the cutting force components. For this purpose, three different proportions of 5, 10, and 15 % MgO-reinforced MMC specimens were produced and their microstructures were examined. At the second stage of the study, three different cutting tools of carbide (C), cubic boron nitride and coated cubic boron nitride at 150, 200, 250 and 300 m/min cutting speeds, 0.075, 0.15 and 0.225 rev/min feed rates and 1 mm depth of cut were used. Then machining tests were carried out for every reinforcement proportion of the composite specimens. Three cutting force components were measured during the tests. According to the test results, the most homogeneous composite material in the distribution of reinforcement element was obtained at the 15 % MgO-reinforced sample. While the ratios of F-f and F-r cutting forces to F-c main cutting force are generally F-f = 0.2-0.3 F-c and F-r = 0.1-0.2 F-c, composite materials produced in this study displayed very different results than those suggested by theoretical approaches. When the relationships of F-f feed force and F-r radial forces with F-c main cutting force were interpreted, it was seen that F-f was about 55-73 % F-c and F-r was about 51-63 % F-c. In terms of the force components, the most stable results were obtained with C tools and 10 % MgO-reinforced composite specimens.