The invention relates to a cylinder head of a liquid-cooled internal combustion engine, wherein the cylinder head (1) has a cooling chamber arrangement (5) which is connected to a fire-proof plate (3)and is divided by an intermediate plate (4), which is arranged substantially parallel to the fire-proof plate (3), into a lower partial cooling chamber (5A) and an upper partial cooling chamber (5b),wherein the upper partial cooling chamber (5b) is arranged on one side of the intermediate plate along the cylinder axis away from the fire-proof plate, and the upper (5b) and the lower partial cooling chamber (5A) are flowing connected via at least one overflow opening extending around the cylinder axis, and the overflow opening is preferably arranged next to a receiving sleeve. The aim of the present invention is to provide a cylinder head which has optimum cooling of regions which are subject to high thermal stress. This object is achieved according to the invention in that the overflow opening has at least one annular section which extends around the cylinder axis in a circular shape and a protruding portion (6b) extending from the annular section and pointing away from the cylinder axis (2) in the radial direction.