A data slot allocation method for a stream delivery in an ultra wide band (UWB) wireless personal area network (WPAN) based on an ad-hoc network of a distributed network topology. The number of data slots allocable to each stream, including a new stream, to be transferred is calculated. The necessary data slots are relinquished to the new stream from existing streams when the number of the allocable data slots is less than a number of preset data slots of the new stream.