Abstract: Leaf-shape is a significant feature for plant recognition. Establishing computer recognition system is an essential topic for identifying plants. Image processing, feature abstraction and classification of plant leaf shape with computer recognition system were discussed in this paper. The system has been developed with Microsoft Visual Basic.Net under Windows 2000/XP system. It can accomplish leaf image input, transform, smoothness, segmentation and finding leaf margin, etc. The performance of the system to recognize leaf shape has been demonstrated with 93.8% precision rate through testing 337 samples which belong to 14 species of plants. This work is very essential for further studies.