Rock mechanics is the fundamental theoretical knowledge for civil engineering, geological engineering and other related disciplines, also an important major course for undergraduate. Through long-term practical experience of teaching and scientific research for rock mechanics, three significant concepts for undergraduate teaching are summarized: Highlight the complexity of rock mass, emphasis on practicality of rock mechanics theory, expound the prospective of rock mechanics development. Through actual proof, combining these three concepts with teaching will be more conducive to help students mastering the essence of the knowledge system for rock mechanics.