PURPOSE: To provide an engine cooling structure for a water surface traveling ship by which the muffler side can be cooled sufficiently even by a small quantity of cooling water.

CONSTITUTION: In an engine cooling structure for a water surface traveling ship to cool an engine for the water surface traveling ship, which has an engine body for the water surface traveling ship having a cylinder block 21, a cylinder head 22 and a head cover 22a and a muffler 27 of the engine body, by cooling water from a cooling pump 60, a joint 61 is arranged to branch off the cooling water from the cooling pump 60 to the engine body side and the muffler 27 side.