There is provided an engine cooling device equipped with a rotatable fan for cooling engines. The fan comprises a driving shaft, a turbine hub part supported on a driving shaft and a plurality of blades mounted on a turbine hub part. A posture switching mechanism of a fan provided is capable of switching postures of said blades between the first posture when a cooling of engines is preforming and the second posture when the retrorse wind in contrast to that in the first one occurs, by a rotation of driving draft circling its circumrotatory axis in a direction to the core. The posture switching mechanism comprises a driver, a rotating part supported on the driver, and a blades operation unit between the rotating part and the turbine hub part. Each blade is capable of switching between the first posture and the second posture through the blades operation unit by relative shift between a rotating part connected to the driver and the turbine hub part.