It is crucial to investigate essential information for comprehending contents of technical documents and academic papers in order to write a paper as novices. The previous works revealed the importance of grasping the logical structure and the knowledge of technical terms in the domain-specific field. As it takes a lot of time to acquire the knowledge of technical terms, a method which can be assumed the meaning of technical terms requires for effective reading. In this paper, we attempt to extract and analyze expression patterns of establishing discourse structure and reflecting author's intention in the Section Introduction of academic papers. The analysis carried out using by original categorization based on the existing model and reported the results.