Provided is a storage controller capable of improving the access performance to the storage device by preventing an I/O access request to the storage device from being concentrated on certain I/O processors among a plurality of I/O processor, and causing the plurality of I/O processors to issue the I/O access request in a well balanced manner. With this storage control system, a plurality of stripe units are formed by striping the logical volume into a stripe size of an arbitrary storage capacity, and information regarding which I/O processor among the plurality of I/O processors will output the I/O request to which stripe unit among the plurality of stripe units is stored as the control information in the memory.