Automatic abstraction can automatically extract the brief and coherent essays reflecting the main contents of the text completely and accurately from the text or text collection by using the computer to meet the general or particular users’ requirements．First，this paper refers to the definition，function and classification of automatic abstraction，and then gives a kind of automatic abstraction technology based on keywords retrieval．It also puts forward a method of detecting plagiarism in the theses based on automatic abstraction and analyzes the results of the experiment．Finally，the authors summarize this paper and introduce the further work in brief．