Abstract: The application of near ground UAV and the development of outer space activities pose many challenges to the construction of aerospace law. However, the current law does not clearly define the specific connotation of the concept of airspace, and the current academic research also confuses the concept of airspace, territorial airspace and air space, which objectively delays the development of aerospace law. Therefore, first of all, we should start from the perspective of the subject of airspace rights by taking the interest demands of the subject of airspace rights as the definition perspective; secondly, we should distinguish the defects of air space theory, the relationship between airspace and territorial airspace, and then clarify the specific connotation of airspace concept.