A method for managing system resources in a network system in which a digital interface is used for connection is provided. The method for managing system resources required for communication between a source device and a sink device includes the steps of (a) initially allocating system resources presently required to the source device, (b) monitoring the format of the output bit stream of the source device in a state in which communication between the two devices is maintained, (c) allocating additional system resources to the source device or releasing redundant system resources from the source device, under the lead of the source device when it is determined as a result of monitoring that the requirements for system resources have changed, and (d) detecting final system resources and releasing the detected system resources when communication between two devices is terminated.