Recently

the ultra-wide band （UWB）-based technique is focused on more deeply along with the design of MAC （media access control） for its advantages.Comparing with the conventional wireless communication system

the UWB system has its unique characteristics

higher speed rate

lower PSD （power spectrum density）

etc.It is therefore necessary to propose advanced MAC protocols for matching the requirements of the system.In this study

the performance of various types of MAC protocols based on UWB system is investigated.The physical structures for different MAC protocols are compared.Some special demands from UWB for MAC are analyzed.The advanced design for the MAC protocols in UWB is proposed.It may provide the implementation base for future MAC protocols.