To restrain a catch of a door latch and the increase of battery power consumption which are easily caused during keyless operation in a direct sensor system and a preliminary authentication system, respectively, in a door locking/unlocking control device.

When an operator touches a door handle during the keyless operation in the direct sensor system, a door unlocking control signal is output from an on-vehicle unit provided ID information included in a reply signal transmitted from a portable device in response to a reply request signal transmitted from the on-vehicle unit conforms to the ID information in the on-vehicle unit. When it takes more time than a predetermined time before the door is opened from the output of the door unlocking control signal, the keyless operation in the preliminary authentication system starts (S8, S11) based on a judgement that the door latch is caught, and the catching of the door latch is restrained thereafter. Unless the predetermined number of times or more of the door latch catching is detected, the keyless operation in the preliminary authentication system stops (S16, S17) and the battery power consumption for the transmission of the reply request signal is restrained.