The disclosure is related to a method and a system for managing viewability of a location-based spatial object. The system provides subscribers to set up searching criteria for every spatial object through the viewability management mechanism. A viewable range for a spatial object is such as a spatial range, a user range and/or a time range. While the system inspects the spatial information and searching criteria of the spatial objects registered in a database, it may be found that the viewable ranges of multiple spatial objects are interfered under the same searching criteria. Thus, the system allows the subscribers to assign ranking weights to different spatial objects for giving them different values. As a result, the system adjusts an order to display the multiple spatial objects according to their ranking weights under the same searching criteria. A search result is displayed through an augmented-reality technology in a terminal device.