To provide a synchronization control device for a vehicle which can improve durability of a synchronizing mechanism.

A device has a synchronizing mechanism, electric motor 51 connected to an input shaft of a speed changer 12, shift operation detection means detecting a lever is existed in a passing specific preliminary position before the lever arrives to a specific gear position, input shaft rotational speed detection means 80 detecting an input shaft rotational speed of the transmission 12 and a control device. In the control device, when the lever is existed in a specific preliminary position is detected by the shift operation detection means, based on the input shaft rotational speed and gear ratio, an input shaft rotational speed after a shift is estimated, during the time a clutch device 14 is released, so that the input shaft rotational speed comes to be the estimated input shaft rotational speed, the electric motor 51 is synchronously controlled.