A stream scheduling system capable of lowering a probability for a response time of a real time stream server to exceed a specified time limit. A reference for transfer timing (reference time-slot) which can guarantee a continuity of a stream for the requested real time stream data is determined, and a transfer timing is determined in a prescribed relation to the reference time-slot while a reading timing is set movably within a prescribed tolerable range defined with respect to the reference time-slot. When a request for a transfer of a new real time stream data is received, a time-slot for a reading of another real time stream data is re-allocated within a prescribed tolerable range defined with respect to the reference time-slot for that another real time stream data so as to create a vacant time-slot, and a reading of that new real time stream data is allocated to the vacant time-slot created by re-allocation.