A method for managing a schedule based on a user's location information by a system for managing a schedule. The method comprises receiving a schedule including at least one of an appointment location, appointment contents an appointment time, and appointment target person's phone number from the user; registering the schedule which includes the user's location information by a schedule registration unit of the system; detecting the user's location by a location detection unit of the system; and sending a message related to the schedule or the user's location by a sending unit of the system. The sending of the message related to the schedule or the user's location by the sending unit of the system sends information of a changed appointment time and place to the appointment target person when the user changes the appointment schedule.