A management server includes a storage unit, a sub-server and a load balancing unit. The storage unit stores a datum. The sub-server is corresponded to the storage unit and obtains the datum from the storage unit according to a request signal. The load balancing unit is coupled to the sub-server and receives the request signal from the client. The load balancing unit distributes the request signal to the corresponding sub-server according to a request number of the request signal. The management server outputs the datum obtained by the sub-server from the storage unit according to the request number.