On the basis of the character description of symptom of vegetable diseases and insect pests, by using methods and technology of knowledge engineering, with the help of the technology of Neural network, uncertainty reasoning, Multi media, friendly human computer interface, and cooperative conflicts resolution, the diagnose expert system framework for vegetable diseases and insect pests is implemented. The gradually learning and removing redundant samples with Rough sets theory is used in this Neural Network. The neural network was trained with the fact provided by the field expert in order to input symptom of vegetable diseases and insect pests visually.The way of inputting is choosing method. Prompting templets or object demonstration is lined out by the selecting button to help users to input conveniently. Using this framework, the diagnose Expert System of tomato diseases and insect pests was worked out.