According to the relation of bridge with water，an object-oriented method to extract bridges from high resolution remote sensing image is put forward as follows.First，use the object-oriented image analysis method to classify the IKNOS image into two classes，water and the land.Second

export all the image objects of land class to a vector shape file.Then binarize the classified image as two parts，the land with white color and the water with black color.Fourth

process the binarized image based on mathematic morphology to get the connected water object.Fifth

extract the water object to a vector file.Finally，the destired bridge is extracted through the intersection of the land and water vector files.An experiment indicates that the method is of universal application with the features of simplicity，small amount of computation and high efficiency.