To provide a clutch system having improved operational performance and durability.

The clutch system selectively transmits power in the inside of an automatic transmission. The clutch system includes a rotation shaft rotated by the power, at least one plate disposed at the outside of the rotation shaft and moved in the axial direction of the rotation shaft, at least one disc disposed at least between a pair of plates so as to be moved in the axial direction of the rotation shaft and provided with at least one flex in the radial direction, and a piston applying force to the disc in the axial direction of the rotation shaft so as to generate the frictional force between the plate and the disc.