A door latch device in a motor vehicle comprises an engagement portion including a latch which engages with a striker of a vehicle body. The door latch device comprises an inner lever connected to an inside handle, a lock lever connected to a lock knob on a door inside the vehicle, a subsidiary lever connected to the lock lever, a childproof lock lever, a motor and an actuating member driven by the motor to actuate the childproof lock lever. Childproof locking and a double locking can be carried out by the single motor.