The subject of this paper are the shaft line bearings and stern tube bearings. Shaft line is basic part of ship's propulsion system which main function is to trasnfer the torque from propulsion machine to the ship's propeller. For torque to be successfully transfered it is crucial that main shaft is based correctly in order to prevent it's flexion and to enable swimmingly rotation with as less as posible transmission losses caused by friction. That is achieved by placing the bearings. These are the machine elements designed specially to enable the shaft rotation. The bearings can be divided in several categories. Thrust bearing will be mentioned as a specific part of the shaft line which annul's both the radial an axial forces. Stern tube is the aftermost part of the shaft line. It is equiped with bearings which are enableing the shaft rotation and with the seals which are preventing the sea water to penetrate inside the ship hull and machinery spaces. The stern tube bearings can be lubricated by oil or sea water. They can be made of metal allures or non metal materials.