Moving object identification and tracking by computer vision plays an important role in surveillance using mobile robots. In this paper, a new method for moving object tracking using an adaptive colour filter is introduced. This method is capable of identifying the most salient colour feature in the moving object and using this colour feature to track the object. This method is also capable of adapting this selected colour feature when the surrounding condition is changed. Experimental results have shown that the proposed method can perform robustly in tracking a moving object using a robot mounted camera in a crowded environment.