Abstract: By the study of image processing in the field of data parallel computation, an algorithm-oriented mathematical model of SIMD computer, and a novel method which is useful for mathematical description of data parallel algorithm are proposed. By using the method proposed, detailed descriptions of data parallel algorithm o n histogram operation, region-growing image segmentation and image convolution o peration are given. This mathematical description method is simple and accurate, the communication complexity and computation complexity of the algorithm being studied can be obtained easily in the mathematical formula. The method can be us ed as mathematical description in applications of data parallel algorithm studie s.