Provided is a copy pair monitoring method which is for a storage system having at least one host computer, at least one storage subsystem, and a management computer, the storage subsystem including volumes storing data requested by the host computer to be written, the management computer being accessible to the host computer and the storage subsystem. The copy pair monitoring method is characterized by including the steps of: obtaining every piece of copy pair definition information that is stored in the host computer; removing duplicate copy pair definition information from the whole copy pair definition information obtained; and collecting the copy pair status based on the obtained copy pair definition information from which duplicate copy pair definition information has been removed.