An object of the present invention is to provide a mobile communication system, a detection server, a control apparatus, a mobile communication apparatus, a network optimizing method, and a program which can execute optimization of network processing based on a change of use characteristics. A mobile communication system according to the present invention includes: a detection server that detects a characteristics change of a mobile communication apparatus based on an event notice transmitted from the mobile communication apparatus; and a control apparatus that determines control contents related to the mobile communication apparatus based on the characteristics change of the mobile communication apparatus detected by the detection server, and sets the determined control contents to a processing node that executes data transfer processing between the mobile communication apparatus and another mobile communication apparatus or control processing related to the data transfer processing.