An accounting system includes a plurality of host computers, an accounting server connected to the plurality of host computers, a storage control device connected to the plurality of host computers and the accounting server and having a plurality of channel ports for performing data input/output operation, storage devices connected to the storage control device for storing data inputted/outputted to/from the plurality of host computers, an accounting data generating unit for generating accounting data containing at least one of number of times of access and a data transfer quantity for every accounting subject control unit, and a transfer unit for informing the accounting server of the accounting data generated by the accounting data generating unit, executing the accounting process for the plurality of accounting subject control units.