Abstract: The system for automated selection of mechanisms is divided into problem space and solution space and a mode for automated selecting mechanisms is set up, which is based on set theory and a working means of that man cooperates with computer. From problem space to solution space, different mapping ways are used for kinematical characteristic and function quality. Namely computer selects the mechanisms satisfying kinematical function request by exactly inference. These mechanisms form a new solution space Ω' J. According to the function quality of the mechanisms in Ω'J man selects the usable mechanisms tallying with the request of function quality and a optimum mechanism from Ω' J. Therefore, the difficult problem of standardized describing the request of selecting mechanisms and the information of a mechanism is solved. According to the advanced principle, the automated selection of mechanisms has good come true.

Key words: Automated selection, Mechanism, Set theory