The present invention has the aim of providing a method of an activity information notification service in which a server can receive activity information from a user of a target terminal, depending on his or her privacy setting, and then transmit the received activity information to a selected receiving user, and in which any receiving user can transmit a notification request to a target user in order to receive desired activity information. According to an embodiment of the present invention, a method of an activity information notification service at a server, the method includes steps of receiving activity information from a target terminal; determining a receiving terminal to which the received activity information will be transmitted, depending on a privacy setting of the target terminal stored in a storage unit; and transmitting the activity information to the determined receiving terminal.