Abstract: A new method,Cognitive Agent for image segmentation,is proposed.Then,the basic principle and the main idea of this method are introduced.There are four kinds of pheromones,i.e.pixel's gray local mean value,pixel's local standard deviation,pixel's local energy and pixel's local fractal value;which are extracted in neighbour pixels of each pixel and then regarded as the criterion of thinking,reasoning and decision-making of Cognitive Agent for selecting homogeneous pixels.The method is tested on three aerial images;and the experiments show that this proposed method is reasonable and promising in the future.