To provide an engine cooling device for a vehicle which rationally integrates a water temperature sensor by suppressing the dispersion of cooling water temperature when an engine is cold and by simplifying a cooling water passage.

The engine cooling device forces cooling water to flow into the upstream side tank 31a on the upstream side of the radiator core (a heat exchange part) 31c of a radiator 31 through the medium of a radiator introduction hose 46 extending from a main outflow part 45 in a thermostat 41 when the engine is hot, and blocks the main outflow part 45 and forces cooling water to flow into the downstream side tank 31b on the downstream side of the radiator core 31c of the radiator 31 through the medium of a bypass hose 52 extending from a sub-outflow part 51 in a thermostat 41 when the engine is cold.