As commercial facilities become ever larger in recent years, parking lots, which are built alongside these facilities, are also growing in size. If the parking lot is congested, drivers often spend a long time looking for vacant parking spaces because they cannot see the entire lot, resulting in an ineffective stay of vehicles in the lot. This paper proposes a distributed vacancy management method using inter-vehicle communication. Specifically, the area of a parking lot is divided into sections and all the vehicles within a section form a group consisting of one parent vehicle and child vehicles. Vacancy is managed using this parent-child relations and group presence information. A model for evaluating staying time of vehicles in the lot has been defined, and the effectiveness of the proposed method has been evaluated using simulation.