A vehicle behavior data storage control system including a storage control device and an ECU is disclosed. Upon determining occurrence of an unexpected behavior, the storage control device stores an unexpected behavior data in a memory and transmits the unexpected behavior data. The ECU determines whether or not the unexpected behavior data matches an estimated behavior data indicative of a behavior estimated to occur due to control processing of the ECU. When both data match each other, the ECU transmits the matching information. The storage control device, upon receipt of the matching information, deletes or permits overwriting the unexpected behavior data stored in the memory.