Abstract: In recent years,much interest focus on planar magnet in microfluidics with the development of MEMS and immune magnetic beads.However their applications are obsessed by the complex fabrication,low caputre efficiency and heat effect.In this paper,we present a rapid fabrication method of three-dimensional micro magnetic structures based on multilayered SU-8 pattern and conventional PDMS molding.By the high-gradient magnetic field induced by an external magnet,magnetic beads are captured by these micro magnetic structures and released when the external magnet is removed.Protein capture is realized on the chip.