The present invention provides an engine cooling apparatus that is capable of suppressing cavitation in a high rotation region while achieving an increase in a circulation flow rate of cooling water in a low/medium rotation region. The engine cooling apparatus includes: a main cooling water circuit that circulates the cooling water between an engine and a radiator; a branch portion provided between the engine and the radiator; a thermostat; temperature detecting means; a first bypass flow passage; a second bypass flow passage that connects the engine to the branch portion; a control valve; a bypass convergence portion; a water pump; valve opening control means; and engine rotation speed detecting means.
