Abstract: An engine cooling structure for a water cooled engine includes water pump and a thermostat. The water pump pumps coolant to a water jacket of the engine. The water pump and thermostat are provided on a cover member installed on an outside of a crankcase of the engine, and a coolant passage, which communicates with the water jacket through the water pump from the thermostat, is integrally formed in the cover member, so as to obtain arrangement of the cooling structure that is efficient in terms of space. The engine cooling structure increases the degree of freedom of layout around a cylinder head by keeping the projection amount on a side of the cylinder head small, simplifies the piping construction, and reduces the number of assembly steps.