Abstract: The present subject matter describes an Auto lock slider plastic slider for a slide fastener. According to one embodiment of the present invention the slider comprises a slider body having one or more slots formed therein. A puller means having a cam provision is integrated with the slider body. In another embodiment the puller means is attached to the slider body and not an integrated part thereof. Further, a resilient locking member having a first end and a second end is attached to the slider body so that the one end gets arrested in one of the slots in the slider body when assembled. Additionally the resilient locking member is adapted to cooperate with the cam provision to affect engaging and/or disengaging of the another end of the resilient locking member with respect to the slide fastener through another slot in the slider body thereby locking or unlocking the slide fastener.