Abstract: Marker-based watershed segmentation can effectively overcome the problem of over-segmentation and performs well in most cases.However it may not be suitable for remote sensing images due to the diversity of ground objects in local and regional scale.Regions with different characteristics can not be segmented with the same criteria arbitrarily.We propose regional adaptive watershed segmentation algorithm.First,a regional adaptive threshold image is constructed using the blurred gradient image combined with an evaluated statistic threshold.Then markers are constructed by threshold segmentation of the gradient image.Segmentation result is finally generated with an marker-based watershed segmentation.The algorithm is proved to be effective through a series of experiments including the comparison with the multi-resolution segmentation algorithm used in eCognition.