Abstract: A fan capable of resisting reversed flow includes a frame body, a fan wheel and at least two baffle parts. The frame body has an inlet and an outlet and provides at least an actuating device at the outlet side. The fan wheel is rotationally attached to the inner side of the frame body and provides a hub and a plurality of fan blades extending outward radially along the periphery of the hub. One of the baffle parts is pivotally connected to the outlet side of the frame body and the first baffle part connecting with the actuating device. When the fan stops running, the other baffle part, which is without connecting with the actuating device, pushes the slide element of the actuating device to slide for the baffle part closing the outlet.