An air-vent of a vehicle includes a front duct configured to change a discharging direction of an air stream horizontally and vertically, a rear duct connected to a rear side of the front duct and a damper hinged to an inside of the rear duct and selectively blocking the air stream, a rotatable knob coupled to a side of the front duct, formed with a hole at a side thereof, and driving the damper, and an angle-restricting device installed at a portion of the front duct, corresponding to the hole of the knob, the angle-restricting device elastically movable, and restricting a rotation angle of the knob.