A context service unit for providing user activity information in a portable terminal, the context service unit comprising: a log database configured to store log data related to a user activity; wherein the log data comprises application related log data or activity log data; and a controller configured to store the log data received from a specific application, to receive a request for the user situation information comprising user activity information and location and movement information of the portable device, to transmit an authority inquiry message; to receive an authority inquiry result message; to determine, by analyzing the authority inquiry result message, whether supplying of the user situation information for the specific application is authorized, to generate user situation information, representing a current status of a user, based on the stored log data, when it is determined that the supplying of the user situation information for the specific application is authorized, and to transmit the generated user situation information to the specific application; wherein the controller is further configured to: display, when the specific application is executed, whether collection and usage of the log data provided from the specific application is to be approved, generate the log data information reference/usage authority registration information corresponding to the specific application, according to an input of the user, and update the user situation information reference/usage authority registration information for the application based on the log data information reference/usage authority registration information. a log database configured to store log data related to a user activity; wherein the log data comprises application related log data or activity log data; and a controller configured to store the log data received from a specific application, to receive a request for the user situation information comprising user activity information and location and movement information of the portable device, to transmit an authority inquiry message; to receive an authority inquiry result message; to determine, by analyzing the authority inquiry result message, whether supplying of the user situation information for the specific application is authorized, to generate user situation information, representing a current status of a user, based on the stored log data, when it is determined that the supplying of the user situation information for the specific application is authorized, and to transmit the generated user situation information to the specific application; wherein the controller is further configured to: display, when the specific application is executed, whether collection and usage of the log data provided from the specific application is to be approved, generate the log data information reference/usage authority registration information corresponding to the specific application, according to an input of the user, and update the user situation information reference/usage authority registration information for the application based on the log data information reference/usage authority registration information. display, when the specific application is executed, whether collection and usage of the log data provided from the specific application is to be approved, generate the log data information reference/usage authority registration information corresponding to the specific application, according to an input of the user, and update the user situation information reference/usage authority registration information for the application based on the log data information reference/usage authority registration information.