We proposed a novel biased optical Kerr gated imaging (BOKGI) method for ultrafast imaging. The imaging performance of the BOKGI system has been investigated. Experimental results showed that by using the BOKGI, the high spatial frequency components of the detected object could be effectively retrieved, which are often filtered by the photo-induced soft aperture in a conventional OKGI system. Comparing with the conventional OKGI method, the BOKGI method could enhance the sharpness of images and provide a higher spatial resolution of the imaging system. In addition, the influence of the biased angle on the BOKGI performance has been also investigated.