Research for expert system of tomato planting, it intents to set up a all around expert decision system combining agriculture knowledge, scientific research production and practical experience with computer technology. This system makes the best of the modern multimedia computer technology, which gathers words, sound and image .It provides visual, intuitive,scientific and convenient environment using. Moreover, it employs theories of Artificial Neural Network and Expert System, combines experience of experts in tomato's field and simulates agricultural experts to guide farmers to plant tomato.