Rough set theory (RST) has been applied successfully to data analysis and data mining. For example, it has been applied to bioinformatics, economics and finance, medicine, multimedia, web and text mining, signal and image processing, software engineering, robotics, power systems and control engineering. However, the structures and the dynamics of the rough sets are still worth exploring. These research results will be greatly contributed to the applications of rough set theory. How to model and simulate data analysis and data mining by the roughy set theory is the main focus of this special session. The scope of the methodologies and ideas may include mathematical foundations of RST such as the point-set topology and dynamical systems, etc. As for the models and applications based on RST, we also look forward to include research related to data analysis and data mining, classifications, reasoning, machine learning, decision supports and uncertainty.