This paper proposes a novel approach of suppressing narrowband interference from a multi - subband convolutional coded orthogonal frequency division multiplexing (OFDM) system. In this system, the convolutional coded data symbols using different coding generators are transmitted in different subbands. By identifying and discarding the interfered subband(s), the interference level can be greatly reduced and the system performance of the OFDM system can be improved. The interference thresholds for discarding the interfered subband(s) are determined through simulations over additive white Gaussian noise (AWGN) channel for demonstration purpose. The principle can also be applied to multipath fading channel.