Metropolitan area network （MAN） has become the major issue concerned by many carriers

in whichtransport project is the major technique. The current transport technique SDH and DWDM is firstlyintroduced in the paper

and then the new transport technique admired by many carriers multiple servicetransportation platform （MSTP） is emphasized

its theory

feature and advantage are analyzed. Lastly

thefuture of transfer technique in MAN is also prospected.