The most notable characteristic of continuous-media data is the existence of timing constraints. To handle such data appropriately, some system support for resource management and QOS control is indispensable. For this reason, we are proposing a "QOS-Ticket" model, which combines resource reservation and daptation. The QOSTicket model has been implemented on RT-Mach. In this prototype, a new thread mechanism, named "Q-Thread," is provided. A Q-TRreadallows a user to specifi the tolerable range of the period and computation time for periodic invocations, and makes it easy to write a continuousmedia session that can control the QOS dynamically. We showed the effectiveness of rhe QOS-ficket model based on a dynamic QOS-control experiment with ourpsototype.