A centrifugal micro fluidic system and a centrifugal magnetic position control device used in the centrifugal micro fluidic system for controlling the position of magnetic beads are provided. The centrifugal micro fluidic system comprising, a rotatable platform; a micro fluidic structure which is disposed in the platform; and a plurality of objects which include functional groups on surfaces thereof so as to capture a target material from the fluid and carry the target material while being suspended in and separated from the fluid in the micro fluidic structure, wherein the movements of the objects are controlled by a force affecting the objects differently compared to the force's effect on the fluid. When the objects are made of a magnetic material, the force may be a magnetic force applied by the centrifugal magnetic position control device.