A protective device for automatic open close umbrellas is revealed. The protective device includes a ratchet mounted in a handle and rotating elastically for retracting or releasing a string, a string whose bottom end is fixed on the ratchet while a top end is fixed on an outer tube of an umbrella shaft or a core tube, and a locking member that is reverse L-shaped and is arranged with an elastic member for turning back therein. The locking member includes an upper part, a lower part, and a middle axle, used as a first-class lever. The upper part is against the bottom of the umbrella shaft so that the fastener can lean against a top surface of the upper part. When the umbrella shaft is gradually folded, the top surface of the upper part of the locking member is separated from the fastener while the bottom of the lower part is locked to one of the ratchet teeth of the ratchet elastically so as to achieve anti-springing effect.