94％。Taking the seeds of “Zhongmian 35” as research objectives, a method of surface damages detection was developed based on morphology of cottonseed by the digital image technology. The boundary was picked up with chain code operator and smoothed by the Fourier operator. Find the tip of the cottonseed after analyzing the curvatures of contour points. Detect the local damaged cottonseeds according to the symmetry of the boundary. Area and elongation were used to identify seriously damaged cottonseeds with statistical method. The experiments show that the detecting accuracy is 94% with 200 damaged cottonseeds and 200 cottonseeds without damages.