Conference Name:International Conference on MultiMedia and Information Technology. Conference Address: Three Gorges, PEOPLES R CHINA. Time:DEC 30-31, 2008. ; In this paper we provide a novel method for symmetry detection in diatom images based on spectrum analysis. We notice that the spectrum of an image has naturally zero point symmetry and that the direction of symmety axis in an image is the same with that in the spectrum of the image. Our method detects perfect and imperfect with more flexibility and efficiency than the traditional ones. Using Fourier Transformation, we turn the imperfect symmetry image into perfect symmetry image, in which the symmetry can be easily detected. And we use some algorithms to locate the symmetry axes, which can save much time and computation. And we give a model application of our method in the field of motion deblurring.