The present invention provides a storage control system that can prevent capacity in a cache memory from being overloaded even when the access performance of a controller in a storage controller to an external storage device in an external storage controller is permanently or temporarily poor.In the storage control system, a first storage controller is connected to a storage device in a second storage controller and the first storage controller is configured to be able to write/read data to/from the storage device in the second storage controller in response to a request from a host device connected to the first storage controller. The first storage controller includes a controller for controlling data transmission and reception between the host device and the storage device in the second storage controller, and a cache memory for temporarily storing the data, and the controller sets a threshold value for storage capacity in the cache memory assigned to the storage device according to the properties of the storage device.