Prof. Yang Chun-yan of Guangdong University of Technology pointed out the four basic characteristics of extension methodology. They are formalized and modeling characteristics, extensible and convergent characteristics, transformable and conductible characteristics, and integral and synthetical characteristics. She considered that the methodology both embodies the ideas on system and macrocosm in ancient China and combines the analysis methods of revertible theory. Extension methods are effective methods in analyzing, transforming, reasoning and judging contradiction problems and generating strategies for solving them.