We report a continuous passive particle focusing method using a novel microchannel with symmetric sharp corners which induce curved streamlines and large centrifugal force on particles. At appropriate flow rate, the centrifugal force generated on particles exceeds the inertial lift force; particles driven by the centrifugal force migrate toward the center of the microchannel, achieving continuous particle focus-ing. With simple structure and operation, this method can be potentially used in particle focusing and ex-traction processes in a variety of lab-on-a chip applications.