Abstract: vestigated. differential The equ the complete sliding state. A circular column＇ s completely rolling in a thin cylindrical shell on a rough horizontal plane is intrack equation of the circular column＇ s mass center in inertial frame of reference is deduced, and the ation of motion of system is given. The period of vibration is calculated when the circular column is in rolling state and compared with the period of vibration when the circular column is in the completely

Key words: cilcular column, cylindrical shell, track equation, vibrating period