Abstarct: Cylinder head gasket is a key part in engine that it’s task is engine sealing. The target of this thesis is to obtain the characteristic curve of the cylinder head gasket in loading-unloading cycle. The experimental tests and finite element studies have been carried out on a case study gasket for a marine diesel engine. The case study is a mextal gasket with a single bead on it. A test device for loading and unloading of the gasket bead was designed and fabricated. In this device the load is concentrated on a limited area of the gasket bead. Further, cylinder head gasket performance was analyzed under localize loading similar to the experimental conditions. In addition, the simulations are performed for loading of 360° bead. The simulation results show that the gasket behavior can be captured with high accuracy using the localized loading results. The experimental test results demonstrate high repeatability of the force-closure curves. Comparison of the experimental and simulation results revealed that for the same load, experimentally obtained bead displacement is more that from simulation. This difference was related to the out of flatness observed in the real gasket. The bead shape has a great influence on contact pressure and spring back. Therefore, several model of bead with different thickness and bead height were simulated and the optimum design was obtained with DOE methods. The results show that with decrease in the thickness and increase in bead high, the spring back is increased. Coating of the gasket surface increase of friction and increase in the inclination of characteristic curve. The results of the Fuji paper test and simulations how that under loading, an auxiliary bead is formed, that acts as a preliminary seal for the combustion pressure wave. So the width of the free edge of the gasket is very important parameter for sealing.