Abstract. This paper presents a novel nonparametric clustering algorithm called evolving mean shift (EMS) algorithm. The algorithm iteratively shrinks a dataset and generates well formed clusters in just a couple of iterations. An energy function is defined to characterize the compactness of a dataset and we prove that the energy converges to zero at an exponential rate. The EMS is insensitive to noise as it automatically handles noisy data at an early stage. The single but critical user parameter, i.e., the kernel bandwidth, of the mean shift clustering family is adaptively updated to accommodate the evolving data density and alleviate the contradiction between global and local features. The algorithm has been applied and tested with image segmentation and neural spike sorting, where the improved accuracy can be obtained at a much faster performance, as demonstrated both qualitatively and quantitatively.