Disclosed are a method and system for operating an unmanned delivery device. One embodiment of the method includes setting at least one sampling section with respect to a travel path to a destination of at least one delivery item, determining a type of the sampling section based on location information and altitude information of the sampling section, setting a traveling range including the at least one sampling section based on the type of the sampling section, generating route information including the at least one traveling range, and providing the route information to the unmanned delivery device.