This paper explores a key technique of identifying and locating the sand exploitation ships using ASAR(advanced synthetic aperture radar) images. Chenglingji of Changjiang River was selected as the research region. One software module is developed with the IDL interactive data language which is a facing matrix, simple visual language. And the paper researches some key techniques based on ASAR images, such as filtration and noise reduction, the processing of image based on morphology, boundary detection, region growth, extraction of ship?ˉ s shape feature and so on. In comparison with the field monitored results, this method can achieve 80%a290% accuracy.