Sliigclki Shiokawa arid lwao Sasasib I k p t . o f P:lectrical lihgineering, Krio [Tiiiversitg, :!-I 1-1 tliyoslii, Koliol~u, Yoltoharna, 223 tJ.IF'iIN. Eniarl: banamori. elec, keio. ac. j p A bsimrtTo handle multicast. t,riifHc:, t,he Slot$t,ed Un-Iiiiffered R.eservat,ion Prot,ocol (SURF) is modified and it,s perforrrianc:e is analyzed. We show t h a t oiir theoretic:al analyris is iisefiil to investigat,e the effect, of rriult,ic:ast, traffic:. We also show that, u n d e r Inillticast, t,riiffic:, tiestinat~ion conflict makes s y s t e m perforrriance tiegrade excessively.In addit.ion, t o alleviate t h e p e r f~r r t i i~l~e degradat,ion iinder niiilt,icast, t,raffic. w e propose a protocol t.o handle rririlt,ic:aat, t,raffic efficiently. I n the prot,oc:ol, corit,rol minislots are divided i n t o t,wo parts a n d one of t h e m is used as cont,ention-less minislots. I n addition, two procedures are a d d e d . We evaliiiite t,he perforrriiinc:e of t,he proposed prot,ocol iinder niiilt,ic:ast, t,raffic: by c:orriguter siniulation. As the result, we show t,liat t h e proposed prot,ocol is useful to improve the t,hroiighput, a n d systerrii delay performance iinder mult,ic:ast, traffic:.