Abstract: Attention assigns the limited processing resources to the information which needs processing finely. This feature can enhance the detection ability and response speed of the visual information processing. In the past few years, the allocation mechanism of attention has received a lot of attention and many approaches have been developed. The authors propose a computer model of directional visual attention, which can simulate biological visual attention systems based on their physiological structure. The proposed model has three layers: visual image inputting layer, object encoding layer and control layer. Visual image inputting layer transforms visual image into retina image through imaging mechanisms of biological retina and adjusts the radius of fovea to cover the attention object currently. Object encoding layer encodes objects in retina image by edge detection with maximum gradient and c-means algorithm firstly, then extracts the fundamental information about each object including color, central, set of edge pixels, etc. Control layer transfers the attention focus according to the characteristics of directional objects in knowledge base. In the control layer the space information is used, the object which is nearest from the focus of attention currently in space position has high priority in processing. Experimental results indicate that the attention focus can be transferred to directional objects with the proposed model.