Abstract: A method performed by a system for providing a parking lot reservation service according to an embodiment of the present disclosure includes a process of receiving point of departure information and destination information from a user device, a process of identifying, based on the received destination information, real-time parking space information of each of at least one parking lot located within a reference distance from a location of the destination information, a process of determining at least one candidate parking lot from among the at least one parking lot, a process of transmitting the point of departure information and the destination information to a traffic information system and receiving an estimated time of arrival which has been calculated by the traffic information system based on the point of departure information and the destination information, a process of calculating, based on big data stored in a database, an estimated available parking space of each of the at least one candidate parki