Ontology evolution has become more and more important in domain ontology research. The evolution requirements are the basis of Ontology evolution. This paper gives the model for auto-generated require- ments of domain ontology evolution based on text. First, it extracts relevant concepts from natural text, and then uses the weighted-frequency-algorithm to determine whether the relevant concepts are the key concepts. Last, it combines the ontology-search-algorithm with the rules of evolution requirements, and automatically generates the requirements of ontology evolution.