Abstract: The disclosure relates to an object tracking system and method thereof. The object tracking system can track at least one positioning device through a mobile device. The mobile device includes a processing component coupled to a storage component, a master communication component, a display component, and a control component. Every positioning device includes a processing unit coupled to a control unit, a memory unit, and a slave communication unit. Accordingly, the object tracking system and method thereof may verify the current location of the positioning device, the distance between the mobile device and the positioning device as well as instantly obtain the surrounding information of the positioning device. Additionally, the positioning device may also call the mobile device thereby achieve two-way communication.