Abstract: Ultra-wideband communication system is generally organized in the form of Ad hoc network. In this paper, two strategies of admission controlthe throughput control on overall network or each link, are simply analyzed for Ad hoc network which uses DS-UWB technology as PHY layer. According to the requirements of Quality of Service (QoS) on each link, the number of admitted users in the networks is simulated under perfect power control. It shows that the factors affecting the quality of links such as the periods of orthogonal code and signal to noise ratio have large influence on the number of the admitted users in the UWB Ad hoc networks.