Abstract: A key structure of a computer keyboard includes a cap and a post axially extending from an underside of the cap and being movably inserted into and received in a guide channel of the keyboard. The post has a quadrilateral cross section having pairs of opposite first and second side faces. Each first side face forms two first resilient members each having a contacting portion of a V-shaped configuration laterally extending beyond the post for biasingly engaging with a corresponding inside surface of the guide channel thereby stabilizing the movement of the key with respect to the guide channel and thus reducing the noise level thereof. Each second side face forms a second resilient member defining an elongate slot movably receiving and engaging with a corresponding stop block formed inside the guide channel. The engagement between the slot and the stop block limits the stroke of movement of the key thereby preventing the post from severely impacting and thus damaging the keyboard and associated parts thereof.