The　fractional　arboricity　of　a　graph　G,　denoted　by　Γf　(G),　is　defined　asΓf(G)=maxH⊆G,v(H)>1e(H)v(H)−1.　The　celebrated　Nash-Williams’　Theorem　states　that　a　graph　G　can　be　partitioned　into　at　most　k　forests　if　and　only　if　Γf　(G)≤k.　The　Nine　Dragon　Tree　(NDT)　Conjecture　[posed　by　Montassier,　Ossona　de　Mendez,　Raspaud,　and　Zhu,　in　“Decomposing　a　graph　into　forests”,　J.　Combin.　Theory　Ser.　B　102　(2012)　38-52]　asserts　that　if　Γf(G)≤k+dk+d+1,　then　G　decomposes　into　k+1　forests　with　one　having　maximum　degree　at　most　d.　In　this　paper,　we　prove　the　Nine　Dragon　Tree　(NDT)　Conjecture.　©　2016,　János　Bolyai　Mathematical　Society　and　Springer-Verlag　Berlin　Heidelberg.