The invention relates to a noise reducing structure of a speed reduction device for electric CVVT. A noise reducing apparatus of a speed reduction device for electric continuous variable valve timing (CVVT), may include the speed reduction device having an inner tooth portion formed to be faced opposing an external wheel of a ball bearing in an interior diameter surface of a housing that may be integrally formed with a sprocket and rollers arranged through a cage between an inner tooth of the inner tooth portion and the external wheel of the ball bearing, wherein a coating layer may be formed to ease impact in exterior circumference portions of the rollers.