Multimedia databases may require storage space so huge that magnetic disks become neither practical nor economical. Hierarchical storage systems provide extensive storage capacity for multimedia data at very economical cost, but the long access latency of tertiary storage devices and large disk buffer make them infeasible for multimedia databases and visual information systems. In this paper, we investigate the data striping method for heterogeneous multimedia data streams on HSS. First, we have found that the multimedia objects should be striped across all media units to achieve the highest system throughput and smallest disk buffer consumption. Second, we have proved a feasibility condition for accepting concurrent streams. We have carried out experiments to study its performance, and it is observed that the concurrent striping method can significantly increase the system throughput, reduce the stream response time, and lower the need for disk buffers, offering considerable advantages and flexibility.