A self-moving device for movable furniture parts includes a movable part which is movable with respect to a stationary part. The movable part includes first and second connecting portions. A closing mechanism includes a slide base which is movable in response to a force generated by a first elastic member. A locking member connected to the slide base is adapted to engage with the first connecting portion so that the movable part is urged by the first elastic member to be self-closing with respect to the stationary part. An opening mechanism includes a push member urged by a second elastic member to act on the second connecting portion. The movable part may be pushed by an external force to disengage the locking member from the first connecting portion so that the movable part is urged by the second elastic member to be self-opening with respect to the stationary part.